Ultralow-Content Palladium Dispersed in Covalent Organic

Article Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX

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Ultralow-Content Palladium Dispersed in Covalent Organic Framework for Highly Efficient and Selective Semihydrogenation of Alkynes Jian Hong Li,†,‡,⊥ Zhi Wu Yu,§,⊥ Zhi Gao,‡ Jian Qiang Li,‡ Yuan Tao,‡ Yu Xin Xiao,‡ Wen Hui Yin,‡ Ya Ling Fan,‡ Chao Jiang,‡ Li Jun Sun,‡ and Feng Luo*,‡ †

China Institute of Atomic Energy, Beijing 100822, P. R. China State Key Laboratory of Nuclear Resources and Environment, School of Chemistry, Biology and Materials Science, East China University of Technology, Nanchang 330013, P. R. China § High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, Anhui, P. R. China

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S Supporting Information *

ABSTRACT: Developing noble-metal-based catalysts with ultralow loading to achieve excellent performance for selective hydrogenation of alkynes under mild reaction conditions is highly desirable but still faces huge challenges. To this end, a SO3H-anchored covalent organic framework (COF-SO3H) as the support was deliberately designed, and then ultralow-content Pd (0.38 wt %) was loaded by a wet-chemistry immersion dispersion method. The resulting Pd0.38/COF-SO3H composite exhibits outstanding performance for the selective hydrogenation of phenylacetylene with 97.06% conversion and 93.15% selectivity to styrene under mild reaction conditions (1 bar of H2, 25 °C). Noticeably, the turnover frequency value reaches as high as 3888 h−1, which outperforms most of reported catalysts for such use. Moreover, such a catalyst also exhibits excellent activity for a series of other alkynes and high stability without obvious loss of catalytic performance after five consecutive cycles.

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INTRODUCTION The selective hydrogenation of alkynes to alkenes without deep hydrogenation to alkanes lies at the heart of the industrial manufacturing of fine chemicals, pharmaceuticals, nutraceuticals, and agrochemicals.1−4 However, their efficiency is often seriously hindered by the inevitable deep hydrogenation of alkynes into undesirable alkanes.5 Up to now, extensive efforts have been devoted to improving the catalytic efficiency of alkyne hydrogenation. Among different metal-based catalysts, noble-metal (Pt, Pd, Au, etc.) catalysts are the more ideal choice because of their high catalytic activity and durable stability. Compared to other noble-metal catalysts, Pd-based catalysts are considered to be more suitable alternatives owing to their strong dissociative ability for H2 and relatively cheap cost.6 As is well-known, support materials play a crucial role in the catalytic performance because a suitable support often leads to strong interaction between the active metal and support, which is good for enhancing the catalytic activity.7−10 Thus, a variety of different supports including porous silica,11 carbon materials,12 graphene,13 metal oxide,14 polymers,15 and metal−organic frameworks (MOFs)16 have been used to © XXXX American Chemical Society

load noble-metal Pd for the selective hydrogenation of alkynes. For example, Ulan et al. reported a CaCO3-supported Pd catalyst (Pd/CaCO3 treated by Pb salts) for the selective hydrogenation of 2-hexyne.17 Unfortunately, this catalyst suffers low selectivity to 2-hexene (about 60%) and poor stability, as well as high toxicity because of the existence of toxic Pb, which seriously limits its further large-scale application. Considering that bimetallic catalysts generally exhibit more excellent catalytic activity compared to monometallic catalysts because of the distinct electronic interaction between different metals, an active carbonsupported Pd-based bimetallic catalyst (Pd0.33Pb0.67/C) was constructed for the selective hydrogenation of phenylacetylene, which exhibits high conversion (98%) and selectivity to styrene (99%).18 However, the content of Pd in Pd0.33Pb0.67/C is as high as 10.64 wt %, resulting in high cost. In recent years, developing a Pd-based catalyst with extremely low loading attracted significant attention.19,20 For example, Pd/Ni(OH)2 with an ultralow content of Pd (only 0.005 wt %) was Received: April 17, 2019

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DOI: 10.1021/acs.inorgchem.9b01117 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry Scheme 1. Procedure for the Synthesis of Pd/COF-SO3H

thus improving the catalytic activity. For example, Banerjee and co-workers reported COF (TpPa-1)-supported Au and Pd nanoparticle hybrid materials, which show high catalytic activity in nitrophenol reduction and Sonogashira coupling because of the strong synergistic effect, respectively.31−33 In this work, COF-SO3H was synthesized by reacting 2,4,6triformylphloroglucinol and 2,5-diaminobenzenesulfonic acid under solvothermal conditions, and then Pd nanoparticles were loaded onto it to obtain Pd/COF-SO3H with different Pd loadings by a wet-chemistry immersion dispersion method. The as-prepared Pd/COF-SO3H with a Pd loading of only 0.38 wt % exhibits excellent performance for the selective hydrogenation of phenylacetylene with 97.06% phenylacetylene conversion and 93.15% styrene selectivity, as well as durable stability. Characterization results reveal that the outstanding performance is ascribed to the strong synergistic effect between the Pd nanoparticles and COF-SO3H support. To the best of our knowledge, this is the first report about such highly efficient COF-supported Pd-based catalysts with ultralow Pd loading for the selective hydrogenation of alkynes to olefin.

successfully prepared by Hu et al. for the selective hydrogenation of acetylene.21 However, the conversion of acetylene and selectivity for ethylene are not satisfied, at only 80% for both of them. Moreover, the Pd@Zn-MOF-74 catalyst with a low Pd loading of 1.67 wt % was prepared and exhibits extremely high phenylacetylene conversion (100%) and styrene selectivity (92%).22 However, a long reaction time and a complex preparation process are necessary, which hinders its large-scale application. Thus, it is highly desirable to develop a promising catalyst with an ultralow content of Pd based on a facile and convenient synthesis strategy for a highly efficient catalytic hydrogenation of alkynes to the desirable olefin. In the recent years, covalent organic frameworks (COFs), established as an emerging class of crystalline porous polymers with high surface area, structural diversity, and designability, attracted much interest and exhibited huge potential in the catalytic field. The distinct advantage is the atomically precise integration of pure organic units to create predesigned skeletons and nanopores based on reticular chemistry,23−30 which can significantly enhance the metal−support interaction, B


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Inorganic Chemistry

Figure 1. Space-filling view of the structure of COF-SO3H.

Figure 2. (a and b) SEM images and (c) SEM−EDS mapping of the as-prepared COF-SO3H.

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RESULTS AND DISCUSSION The synthesis process of Pd/COF-SO3H is schematically illustrated in Scheme 1. The whole catalyst synthesis process is divided into three steps. The first step is to synthesize a 2,4,6triformylphloroglucinol organic unit based on hexamethylenetetramine and phloroglucinol using p-phenylenediamine and fuming sulfuric acid to prepare 2,5-diaminobenzenesulfonic acid. Then a SO3H-anchored covalent organic framework (COF-SO3H) was synthesized based on the organic units 2,4,6-triformylphloroglucinol and 2,5-diaminobenzenesulfonic acid under solvothermal conditions. As shown in Figure 1, COF-SO3H shows the eclipsed stacking ABA mode with a stacking distance of 3.4 Å, in which −SO3H units among adjacent layers hold the opposite-side arrangement rather than the common same-side mode. The lattice parameters of a, b, and c in COF-SO3H are 22.499, 22.499, and 6.8 Å, respectively. The as-prepared COF-SO3H is not soluble in water and common organic solvents such as dichloromethane, acetone, ethanol, and tetrahydrofuran, exhibiting promising application as a support. Moreover, COF-SO3H can promote ion exchange between H+ in −SO3H and Pd2+, thus enhancing the interaction of Pd2+ and COF-SO3H and promoting the dispersion of Pd species. Finally, Pd/COF-SO3H was obtained using NaBH4 as a reductant. Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), and N2 adsorption−desorption were investigated to gain insight into

the structural information. The FT-IR spectrum of COF-SO3H (Figure S1) shows the characteristic SO3− stretching vibrations of a sulfonic acid at ∼1048 and ∼1103 cm−1, which match well with those of the sulfonic acid of 2,5-diaminobenzenesulfonic acid, confirming the successful introduction of −SO3H. Meanwhile, the N−H (3444 cm−1) stretch and the characteristic band related to CO (1700 cm−1) were also obviously detected. On the basis of the above IR spectrum results, we can better understand the structure of COF-SO3H and determine its successful synthesis. Furthermore, EDS analysis indicates that the element content agrees well with the values obtained from elemental analysis (Table S1). The SEM images show uniform filiform morphology (Figure 2a,b), and the SEM− EDS mapping images indicate that the as-prepared COF-SO3H is composed of C, N, O, and S elements (Figure 2c). As demonstrated by the X-ray diffraction (XRD) patterns in Figure 3, the as-synthesized COF-SO3H agrees with the simulated COF-SO3H data, strongly demonstrating the successful preparation of COF-SO3H. TGA reveals that COF-SO3H possesses good thermal stability up to 290 °C (Figure S2a), the weight loss of which is less than 15%. Furthermore, the crystalline structures of COF-SO3H after immersion in a strong acid, boiling water, and a strong base, respectively, were evaluated by powder XRD (PXRD) studies (Figure S2b). The results demonstrate that COF-SO3H has ultrahigh chemical stability, exhibiting a huge industrial application prospect. From cross-polarized magic-angle-spinning solid-state 13C NMR spectroscopy (Figure S3), the βC


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Inorganic Chemistry

of Pd with different contents. The slight decrease of the diffraction intensity related to the (100) plane is ascribed to blockage of the pore channel in COF-SO3H by Pd nanoparticles, as demonstrated by the smaller BET surface area after loading of Pd. TGA proves that Pd0.38/COF-SO3H also possesses excellent thermal stabilities up to 350 °C (Figure S5), which meets the demands for potential applications in catalysis. The SEM image discloses that Pd/COF-SO3H still can retain the uniform fiber morphology (Figures 5, S6, and S7). The porosities of these Pd-loaded samples were explored by N2 adsorption at 77 K, and we found that the loading of Pd onto COF-SO3H can significantly reduce its BET surface area (Figure S8). Relative to the BET surface area in COF-SO3H (306 m2/g), the N2 adsorption capacity at 77 K is largely reduced in these Pd-loaded samples, giving BET surface areas of 200, 99.45, and 66.7 m2/g in Pd0.38/SO3H, Pd0.69/COFSO3H, and Pd1.66/COF-SO3H, respectively, most likely due to the occupation of pores by Pd nanoparticles. Correspondingly, Pd0.38/SO3H delivers a smaller pore size (0.97 nm) compared to Pd0.69/COF-SO3H (1.05 nm) and Pd1.66/COF-SO3H (1.3 nm; Figure S9). Typical transmission electron microscopy (TEM) images of Pd/COF-SO3H (Figures 6 and S10) confirm that the sizes of Pd nanoparticles vary with the content of Pd, viz., 2.63 nm for 0.38 wt % Pd/COF-SO3H, 2.98 nm for 0.69 wt % Pd/COFSO3H, and 3.24 nm for 1.66 wt % Pd/COF-SO3H, as revealed by particle size distribution histograms (Figure S11). X-ray photoelectron spectroscopy (XPS) measurements were performed to investigate the electronic state of Pd nanoparticles in Pd/COF-SO3H. As shown in Figure 7, the binding energies of Pd0 related to the typical 3d5/2 peak at 335.68 eV and 3d3/2 peak at 341.03 eV were detected, while Pd2+ with the typical 3d5/2 peak at 337.8 eV and 3d3/2 peak at 342.1 eV were also observed in these Pd-loaded samples.35−38 The presence of Pd0 indicates the successful preparation of Pd nanoparticles, while the formation of Pd2+ may be ascribed to the reoxidation of Pd0 to Pd2+ by air. To verify the catalytic activity of Pd/COF-SO3H, we explored the semihydrogenation reaction. The activity of Pd/ COF-SO3H for the selective hydrogenation of phenylacetylene was performed. Obviously, Pd0.38/COF-SO3H possesses the best performance with phenylacetylene conversion and styrene selectivity compared to Pd0.69/COF-SO3H and Pd1.66/COFSO3H under mild reaction conditions (1 bar of H2, 25 °C, 28 min), which should be attributed to the smallest Pd nanoparticles. Moreover, the activity of Pd-free COF-SO3H was tested under the same reaction conditions, which only exhibits 2.4% conversion even after a reaction of 1440 min, demonstrating that Pd nanoparticles are the key active sites (Table 1). In addition, from Table 2, by a comparison with the reported semihydrogenation experiments of alkynes in the literature, it is clearly suggested that our catalyst presents a highly rare example, showing both high selectivity and conversion for semihydrogenation just based on a single Pd metal with ultralow content. Correspondingly, the ultrahigh catalytic efficiency evaluated by the turnover frequency (TOF) value is up to 3888 h−1, which outperforms most of reported catalysts for such use. On the basis of the catalytic and characterization results presented above, the enhanced performance for Pd0.38/COFSO3H is believed to be related to the following factors. First, the highly dispersed Pd nanoparticles in Pd0.38/COF-SO3H can provide more active sites. Second, the strong interactions

Figure 3. PXRD patterns of the as-synthesized and simulated COFSO3H.

ketoenamine-linked structure in COF-SO3H is further proven.34 What is more, the 77 K N2 adsorption−desorption tests (Figure S4) indicate that the Brunauer−Emmett−Teller (BET) surface area of COF-SO3H is 306 m2/g. Subsequently, a series of Pd/COF-SO3H structures with different Pd contents were prepared by a wet-chemistry immersion dispersion approach. The metal precursor was deposited in the COF-SO3H material by mixing a Pd(NO3)2·xH2O solution with a suspension of COF-SO3H and stirring for 2 h. The mixture was washed by water and methyl alcohol and then reduced with NaBH4 in methanol under a N2 atmosphere to obtain Pd/COF-SO3H. Finally, the mixture was thoroughly washed with water and methyl alcohol and dried before characterization and further use. Inductively coupled plasma analysis demonstrates that the Pd contents in these samples are 0.38, 0.69, and 1.66 wt %, respectively, well consistent with the results obtained by SEM−EDS (Table S2). In order to understand the morphology, chemical composition, and porosities of Pd/COF-SO3H, a series of characterizations were carried out. From the XRD patterns (Figure 4) of COF-SO3H and Pd/COF-SO3H, it can be found that the structure of COF-SO3H was maintained after loading

Figure 4. PXRD patterns of COF-SO3H and Pd/COF-SO3H with different Pd loadings. D


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Inorganic Chemistry

Figure 5. SEM images of (a) Pd0.38/COF-SO3H, (b) Pd0.69/COF-SO3H, and (c) Pd1.66/COF-SO3H. (d) SEM−EDS mapping of Pd0.38/COFSO3H.

Table 1. Activity for the Selective Hydrogenation of Phenylacetylene Using Different Catalystsa catalyst

t (min)

conversion (%)

selectivity to styrene (%)

COF-SO3H Pd2+/COF-SO3H Pd0.38/COF-SO3H Pd0.69/COF-SO3H Pd1.66/COF-SO3H

1440 360 28 28 28

2.424 99.78 97.06 15.69 29.99

100 8.5 93.15 92.89 93.64

a Reaction conditions: phenylacetylene, 1 mmol; ethanol, 15 mL; H2, 1 bar, 25 °C; catalysts, 15 mg.

Figure 6. TEM images of Pd0.38/COF-SO3H.

As is well-known, the stability and reusability of catalysts are the key parameters to determine the prospect of industrial application. The repeated experiment is carried out as follows. The recycled Pd0.38/COF-SO3H catalyst is obtained by centrifugation and dried after the end of the previous reaction. As presented in Figure 8, the conversion of phenylacetylene and the selectivity to styrene exhibit negligible loss even after five successive runs. Further confirmation on the stability is demonstrated by XRD and XPS tests (Figures S14 and S15). Moreover, the BET measurements of Pd/COF-SO3H after the first and fifth cycles were performed. Negligible change of the surface area and pore-size distribution was found (Figures S16 and S17). Also, the morphology was not destroyed after the fifth cycles (Figure S18). The above results demonstrate the high stability of Pd0.38/COF-SO3H.

between the Pd nanoparticles and COF-SO3H support can strengthen the intrinsic activity of a single site, as demonstrated by the high TOF value in Pd0.38/COF-SO3H.46 To further demonstrate the general availability of Pd0.38/ COF-SO3H for semihydrogenation reactions, a series of alkyne substrates were employed as the feedstock. As shown in Table 3, Pd0.38/COF-SO3H also presents an excellent catalytic performance under mild reaction conditions. The alkyne conversion and selectivity to the the target olefin are more than 92%, suggesting its superior application in the field of heterogeneous hydrogenation. As demonstrated by 1H NMR (Figures S12 and S13), the main products for the selective hydrogenation of 2-pentyne and 4-octyne are (Z)-2-pentene and (Z)-4-octene, respectively.

Figure 7. Fine Pd 3d XPS spectra of Pd/COF-SO3H with different Pd contents. E


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Inorganic Chemistry Table 2. Comparison with Other Reported Catalysts for the Hydrogenation of Alkynes content (%) catalyst

bar of H2

T (°C)

Pd /COF-SO3H Pd@mpg-C3N4 C−Pd@C PdCo@AC Pd@Zn-MOF-74 Pd/SiC Pd/ZnO@C Pd9Au1/ZnTi Pd/pph3@FDU-12 Pd/CeO2 PdC0.18 Pd/boehmite/Al2O3

1 1 1 1 1 1 1 1 1 1 1 1

25 30 30 30 40 70 30 45 30 60 30 60

0.38

t (min) 28 85 30 75 720 2880 60 460 480 11.5 80

C

S

TOF (h−1)

ref

97.06 99 62 93 100 90 96 100 92 60 99 90

93.1 97 95 94 90 90 99 90 94 68 99.2 90

3888 72 1128 224 2284 1000 733 2284 560 2639 7896

this work 9 19 20 23 39 40 41 42 43 44 45

Table 3. Activity for the Selective Hydrogenation of Alkynes Using the Pd0.38/COF-SO3H Catalysta

Reaction conditions: alkynes, 1 mmol; ethanol, 15 mL; H2, 1 bar, 25 °C; catalyst, 15 mg.

a

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CONCLUSIONS In conclusion, COF-SO3H was strategically fabricated based on a cheap raw material, and then ultralow-content Pd was loaded onto it to obtain Pd/COF-SO3H. The resulting Pd0.38/ COF-SO3H with a Pd loading of only 0.38 wt % exhibited high crystallinity and thermal stability up to 350 °C and was employed for the selective hydrogenation of a series of alkynes to produce olefins. As expected, different alkynes could be totally converted to the desired olefins with almost 95% selectivity in Pd0.38/COF-SO3H. Impressively, the TOF value for the semihydrogenation of phenylacetylene to produce styrene can reach as high as 3888 h−1, which outperforms most of the reported excellent catalysts. A series of characterizations and experimental results revealed that the excellent catalytic performance in Pd0.38/COF-SO3H is mainly ascribed to small Pd nanoparticles with an average size of 2.2 nm, which can provide more accessible active sites and enhance the metal− support interaction. Moreover, the as-fabricated Pd0.38/COF-

Figure 8. Recyclability of the Pd0.38/COF-SO3H catalyst: conversion, black; selectivity, red.

F


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Inorganic Chemistry

(10) Gao, Z.; Xie, R. F.; Fan, G. L.; Yang, L.; Li, F. Highly Efficient and Stable Bimetallic AuPd over La-Doped Ca-Mg-Al Layered Double Hydroxide for Base-Free Aerobic Oxidation of 5-Hydroxymethylfurfural in Water. ACS Sustainable Chem. Eng. 2017, 5, 5852− 5861. (11) (a) Shang, L.; Bian, T.; Zhang, B.; Zhang, D.; Wu, L. Z.; Tung, C. H.; Yin, Y.; Zhang, T. Inside Cover: Graphene-Supported Ultrafine Metal Nanoparticles Encapsulated by Mesoporous Silica: Robust Catalysts for Oxidation and Reduction Reactions. Angew. Chem., Int. Ed. 2014, 53, 250−254. (b) Wang, H. H.; Liu, Q. Y.; Li, L. B.; Krishna, R.; Wang, Y. L.; Peng, X. W.; He, C. T.; Lin, R. B.; Chen, B. L. A Nickel-4′-(3,5-Dicarboxyphenyl)-2,2′,6′,2′’-terpyridine Framework: Efficient Separation of Ethylene from Acetylene/Ethylene Mixtures with a High Productivity. Inorg. Chem. 2018, 57, 9489− 9494. (c) Gao, Z.; Liu, F. Q.; Wang, L.; Luo, F. Highly Efficient Transfer Hydrodeoxygenation of Vanillin over Sn4+-induced Highly Dispersed Cu-based Catalyst. Appl. Surf. Sci. 2019, 480, 548−556. (12) Joo, S. H.; Choi, S. J.; Oh, I.; Kwak, J.; Liu, Z.; Terasaki, O.; Ryoo, R. Ordered Nanoporous Arrays of Carbon Supporting High Dispersions of Platinum Nanoparticles. Nature 2001, 412, 169−172. (13) Nethravathi, C.; Anumol, E. A.; Rajamathi, M.; Ravishankar, N. Highly Dispersed Ultrafine Pt and Pt Ru Nanoparticles on Graphene: Formation Mechanism and Electrocatalytic Activity. Nanoscale 2011, 3, 569−571. (14) (a) Gao, Z.; Liu, F.-Q.; Wang, L.; Luo, F. Hierarchical Ni2P@ NiFeAlOx Nanosheet Arrays as Bifunctional Catalysts for Superior Overall Water Splitting. Inorg. Chem. 2019, 58, 3247−3255. (b) Gao, Z.; Fan, G. L.; Liu, M. R.; Yang, L.; Li, F. Dandelion-Like Cobalt Oxide Microsphere-Supported RuCo Bimetallic catalyst for highly efficient hydrogenolysis of 5-hydroxymethylfurfural. Appl. Catal., B 2018, 237, 649−659. (15) Huang, Y. B.; Wang, Q.; Liang, J.; Wang, X.; Cao, R. Soluble Metal-Nanoparticle-Decorated Porous Coordination Polymers for the Homogenization of Heterogeneous Catalysis. J. Am. Chem. Soc. 2016, 138, 10104−10107. (16) (a) Yang, Q.; Xu, Q.; Jiang, H. L. Metal−Organic Frameworks Meet Metal Nanoparticles: Synergistic Effect for Enhanced Catalysis. Chem. Soc. Rev. 2017, 46, 4774−4808. (b) Zhu, L.; Liu, X. Q.; Jiang, H. L.; Sun, L. B. Metal-Organic Frameworks for Heterogeneous Basic Catalysis. Chem. Rev. 2017, 117, 8129−8176. (c) Ma, H. F.; Liu, Q. Y.; Wang, Y. L.; Yin, Sh. G. A Water-Stable Anionic Metal-Organic Framework Constructed from Columnar Zinc-Adeninate Units for Highly Selective Light Hydrocarbon Separation and Efficient Separation of Organic Dyes. Inorg. Chem. 2017, 56, 2919−2925. (d) Yang, L. X.; Wu, H. Q.; Gao, H. Y.; Li, J. Q.; Tao, Y.; Yin, W. H.; Luo, F. Hybrid Catalyst of a Metal-Organic Framework, MetalNanoparticles, and Oxide That Enables Strong Steric Constraint and Metal-Support Interaction for the Highly Effective and Selective Hydrogenation of Cinnamaldehyde. Inorg. Chem. 2018, 57, 12461− 12465. (e) Tao, Y.; Wu, H. Q.; Li, J. Q.; Yang, L. X.; Yin, W. H.; Luo, M. B.; Luo, F. Applying MOF+Technique for in Situ Preparation of a Hybrid Material for Hydrogenation Reaction. Dalton Trans 2018, 47, 14889−14892. (f) Xiong, Y. Y.; Wu, H. Q.; Luo, F. The MOF+ Technique: A Potential Multifunctional Platform. Chem. - Eur. J. 2018, 24, 13701−13705. (17) Ulan, J. G.; Kuo, E.; Maier, W. F.; Rai, R. S.; Thomas, G. Effect of Lead Acetate in the Preparation of the Lindlar Catalyst. J. Org. Chem. 1987, 52, 3126−3132. (18) Liu, J.; Zhu, Y. N.; Liu, C.; Wang, X. S.; Cao, C. Y.; Song, W. G. Excellent Selectivity with High Conversion in Semi-Hydrogenation of Alkynes Using Pd-based Bimetallic Catalysts. ChemCatChem 2017, 9, 4053−4057. (19) Yoshii, T.; Nakatsuka, K.; Kuwahara, Y.; Mori, K.; Yamashita, H. Synthesis of Carbon-Supported Pd−Co Bimetallic Catalysts Templated by Co Nanoparticles Using the Galvanic Replacement Method for Selective Hydrogenation. RSC Adv. 2017, 7, 22294− 22300. (20) Bhuyan, D.; Selvaraj, K.; Saikia, L. Pd@SBA-15 Nanocomposite Catalyst: Synthesis and Efficient Solvent-free Semihydrogenation of

SO3H also shows outstanding stability for the selective hydrogenation of phenylacetylene to styrene with negligible loss even after five successive runs. The attractive feature of the present COF-supported Pd-based catalyst provides a guiding principle for future catalyst design.

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ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.9b01117. Figures S1−S11 and Tables S1 and S2 (PDF)

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected] (F.L.). ORCID

Feng Luo: 0000-0001-6380-2754 Author Contributions ⊥

These authors are the cofirst authors.

Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS We thank the National Science Foundation of China (Grants 21871047, 21661001, and U1832148), the Natural Science Foundation of Jiangxi Province of China (Grant 20181ACB20003), and the Technology Program of Education Department of Jiangxi Province of China (Grant GJJ1505).

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REFERENCES

(1) Yu, J. W.; Wang, X. Y.; Yuan, C. Y.; Li, W. Z.; Wang, Y. H.; Zhang, Y. W. Synthesis of Ultrathin Ni Nanosheets for Semihydrogenation of Phenylacetylene to Styrene under Mild Conditions. Nanoscale 2018, 10, 6936−6944. (2) Borodzinski, A.; Bond, G. C. Selective Hydrogenation of Ethyne in Ethene-Rich Streams on Palladium Catalysts. Part 1. Effect of Changes to the Catalyst During Reaction. Catal. Rev.: Sci. Eng. 2006, 48, 91−144. (3) Vilé, G.; Albani, D.; Almora-Barrios, N.; López, N.; PérezRamírez, Z. Advances in the Design of Nanostructured Catalysts for Selective Hydrogenation. ChemCatChem 2016, 8, 21−33. (4) Molnár, Á .; Sárkány, A.; Varga, M. Hydrogenation of Carbon− Carbon Multiple Bonds: Chemo-, Regio- and Stereo-Selectivity. J. Mol. Catal. A: Chem. 2001, 173, 185−221. (5) Shen, Y. L.; Yin, K. J.; An, C. H.; Xiao, Z. H. Design of a Difunctional Zn-Ti LDHs Supported PdAu Catalyst for Selective Hydrogenation of Phenylacetylene. Appl. Surf. Sci. 2018, 456, 1−8. (6) Mitsui, T.; Rose, M. K.; Fomin, E.; Ogletree, D. F.; Salmeron, M. Dissociative Hydrogen Adsorption on Palladium Requires Aggregates of Three or More Vacancies. Nature 2003, 422, 705−707. (7) Gao, Z.; Li, C. Y.; Fan, G. L.; Yang, L.; Li, F. Nitrogen-doped carbon-decorated copper catalyst for highly efficient transfer hydrogenolysis of 5-hydroxymethylfurfural to convertibly produce 2,5dimethylfuran or 2,5-dimethyltetrahydrofuran. Appl. Catal., B 2018, 226, 523−533. (8) Lee, K.; Lee, H. B.; Lee, K. R.; Yi, M. H.; Hur, N. H. Dual Pd and CuFe2O4 Nanoparticles Encapsulated in a Core/Shell Silica Microsphere for Selective Hydrogenation of Arylacetylenes. Chem. Commun. 2012, 48, 4414−4416. (9) Deng, D. S.; Yang, Y.; Gong, Y. T.; Li, Y.; Xu, X.; Wang, Y. Palladium Nanoparticles Supported on Mpg-C3N4 as Active Catalyst for Semihydrogenation of Phenylacetylene under Mild Conditions. Green Chem. 2013, 15, 2525−2531. G


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Inorganic Chemistry

catalysts Via Autoredox Reaction. Adv. Mater. 2017, 29, 1605332− 1605337. (37) (a) Armbrüster, M.; Kovnir, K.; Behrens, M.; Teschner, D.; Grin, Y.; Schlögl, R. Pd-Ga Intermetallic Compounds as Highly Selective Semihydrogenation Catalysts. J. Am. Chem. Soc. 2010, 132, 14745−14747. (b) Li, X.; Wang, Z. N.; Zhang, Z. R.; Yang, G.; Jin, M. S.; Chen, Q.; Yin, Y. D. Construction of Au-Pd Alloy Shells for Enhanced Catalytic Performance Toward Alkyne Semihydrogenation Reactions. Mater. Horiz. 2017, 4, 584−591. (c) Feng, Q. C.; Zhao, S.; Wang, Y.; Dong, J. C.; Chen, W. X.; He, D. S.; Wang, D. S.; Yang, J.; Zhu, Y. M.; Zhu, H. L.; Gu, L.; Li, Z.; Liu, Y. X.; Yu, R.; Li, J.; Li, Y. D. Isolated Single-Atom Pd Sites in Intermetallic Nanostructures: High Catalytic Selectivity for Semihydrogenation of Alkynes. J. Am. Chem. Soc. 2017, 139, 7294−7301. (38) (a) Poudel, B.; Hao, Q.; Ma, Y.; Lan, Y. C.; Minnich, A.; Yu, B.; Yan, X.; Wang, D. Z.; Muto, A.; Vashaee, D.; Chen, X. Y.; Liu, J. M.; Dresselhaus, M. S.; Chen, G.; Ren, Z. F. High-Thermoelectric Performance of Nanostructured Bismuth Antimony Telluride Bulk Alloys. Science 2008, 320, 634−638. (b) Vilé, G.; Almora-Barrios, N.; Mitchell, S.; López, N.; Pérez-Ramírez, J. From the Lindlar Catalyst to Supported Ligand Modified Palladium Nanoparticles: Selectivity Patterns and Accessibility Constraints in the Continuous-Flow Three-Phase Hydrogenation of Acetylenic Compounds. Chem. Eur. J. 2014, 20, 5926−5937. (39) Mashkovsky, I. S.; Markov, P. V.; Bragina, G. O.; Baeva, G. N.; Rassolov, A. V.; Bukhtiyarov, A. V.; Prosvirin, I. P.; Bukhtiyarov, V. I.; Stakheev, A. Y. PdZn/α-Al2O3 Catalyst for Liquid-Phase Alkyne Hydrogenation: Effect of the Solid-State Alloy Transformation into Intermetallics. Mendeleev Commun. 2018, 28, 152−154. (40) Tian, H.; Huang, F.; Zhu, Y. H.; Liu, S. M.; Han, Y.; Jaroniec, M.; Yang, Q.; Liu, H.; Lu, G. Q. M.; Liu, J. The Development of YolkShell-Structured Pd&ZnO@Carbon Submicroreactors with High Selectivity and Stability. Adv. Funct. Mater. 2018, 28, 1801737− 1801747. (41) Shen, Y. L.; Yin, K. J.; An, C. H.; Xiao, Z. H. Design of a Difunctional Zn-Ti LDHs Supported PdAu Catalyst for Selective Hydrogenation of Phenylacetylene. Appl. Surf. Sci. 2018, 456, 1−6. (42) Guo, M.; Li, H.; Ren, Y. Q.; Ren, X. M.; Yang, Q. H.; Li, C. Improving Catalytic Hydrogenation Performance of Pd Nanoparticles by Electronic Modulation Using Phosphine Ligands Alkyne Semihydrogenation. ACS Catal. 2018, 8, 6476−6485. (43) Tanimu, A.; Ganiyu, S. A.; Muraza, O.; Alhooshani, K. Palladium Nanoparticles Supported on Ceria Thin Film for Capillary Microreactor Application. Chem. Eng. Res. Des. 2018, 132, 479−491. (44) Guo, R. Y.; Chen, Q.; Li, X.; Liu, Y. M.; Wang, C. Q.; Bi, W.; Zhao, C. Y.; Guo, Y. J.; Jin, M. S. PdCx Nanocrystals with Tunable Compositions for Alkyne Semihydrogenation. J. Mater. Chem. A 2019, 7, 4714−4720. (45) Wu, Z. L.; Calcio Gaudino, E.; Manzoli, M.; Martina, K.; Drobot, M.; Krtschil, U.; Cravotto, G. Selective Hydrogenation of Alkynes over ppm-level Pd/boehmite/Al2O3 Beads in a Continuousflow Reactor. Catal. Sci. Technol. 2017, 7, 4780−4791. (46) Chong, J. H.; Sauer, M.; Patrick, B. O.; MacLachlan, M. J. Highly Stable Keto-Enamine Salicylideneanilines. Org. Lett. 2003, 5, 3823−3826.

Phenylacetylene under Mild Conditions. Microporous Mesoporous Mater. 2017, 241, 266−273. (21) Hu, M. Z.; Zhang, J.; Zhu, W.; Chen, Z.; Gao, X.; Du, X. J.; Wan, J. W.; Zhou, K. B.; Chen, C.; Li, Y. D. 50 ppm of Pd Dispersed on Ni(OH)2 Nanosheets Catalyzing Semi-hydrogenation of Acetylene with High Activity and Selectivity. Nano Res. 2018, 11, 905−912. (22) Wu, H. Q.; Huang, L.; Li, J. Q.; Zheng, A. M.; Tao, Y.; Yang, L. X.; Yin, W. H.; Luo, F. Pd@Zn-MOF-74: Restricting a Guest Molecule by the Open-Metal Site in a Metal-Organic Framework for Selective Semihydrogenation. Inorg. Chem. 2018, 57, 12444−124447. (23) Feng, X.; Ding, X. S.; Jiang, D. L. Covalent organic frameworks. Chem. Soc. Rev. 2012, 41, 6010−6022. (24) Ding, S. Y.; Wang, W. Covalent Organic Frameworks (COFs): From Design to Applications. Chem. Soc. Rev. 2013, 42, 548−568. (25) Waller, P. J.; Gandara, F.; Yaghi, O. M. Chemistry of Covalent Organic Frameworks. Acc. Chem. Res. 2015, 48, 3053−3063. (26) Jiang, J. C.; Zhao, Y. B.; Yaghi, O. M. Covalent Chemistry beyond Molecules. J. Am. Chem. Soc. 2016, 138, 3255−3265. (27) Dogru, M.; Bein, T. On the Road Towards Electroactive Covalent Organic Frameworks. Chem. Commun. 2014, 50, 5531− 5546. (28) Huang, N.; Wang, P.; Jiang, D. L. Covalent Organic Frameworks: a Materials Platform for Structural and Functional Designs. Nat. Rev. Mater. 2016, 1, 16068−16086. (29) Bisbey, R. P.; Dichtel, W. R. Covalent Organic Frameworks as a Platform for Multidimensional Polymerization. ACS Cent. Sci. 2017, 3, 533−543. (30) (a) Diercks, C. S.; Yaghi, O. M. The Atom, The Molecule, and The Covalent Organic Framework. Science 2017, 355, 923−930. (b) Jin, Y. H.; Hu, Y. M.; Zhang, W. Tessellated Multiporous twodimensional Covalent Organic Frameworks. Nat. Rev. Chem. 2017, 1, 0056. (31) Pachfule, P.; Panda, M. K.; Kandambeth, S.; Shivaprasad, S. M.; Díaz, D. D.; Banerjee, R. Multifunctional and Robust Covalent Organic Framework−Nanoparticle Hybrids. J. Mater. Chem. A 2014, 2, 7944−7952. (32) Pachfule, P.; Kandambeth, S.; Dı ́az Dı ́az, D.; Banerjee, R. Highly Stable Covalent Organic Framework−Au Nanoparticles Hybrids for Enhanced Activity for Nitrophenol Reduction. Chem. Commun. 2014, 50, 3169−3172. (33) Lu, S. L.; Hu, Y. M.; Wan, S.; McCaffrey, R.; Jin, Y. H.; Gu, H. W.; Zhang, W. Synthesis of Ultrafine and Highly Dispersed Metal Nanoparticles Confined in a Thioether-Containing Covalent Organic Framework and Their Catalytic Applications. J. Am. Chem. Soc. 2017, 139, 17082−17088. (34) Shinde, D. B.; Sheng, G.; Li, X.; Ostwal, M.; Emwas, A.-H.; Huang, K.-W.; Lai, Z. P. Crystalline 2D Covalent Organic Framework Membranes for High-Flux Organic Solvent Nanofiltration. J. Am. Chem. Soc. 2018, 140, 14342−14349. (35) (a) Vilé, G.; Albani, D.; Nachtegaal, M.; Chen, Z. P.; Dontsova, D.; Antonietti, M.; López, N.; Pérez-Ramírez, J. A Stable Single-Site Palladium Catalyst for Hydrogenations. Angew. Chem., Int. Ed. 2015, 54, 11265−11269. (b) Liu, Y. X.; Liu, X. W.; Feng, Q. C.; He, D. S.; Zhang, L. B.; Lian, C.; Shen, R. G.; Zhao, G. F.; Ji, Y. J.; Wang, D. S.; Zhou, G.; Li, Y. D. Intermetallic NixMy (M = Ga and Sn) Nanocrystals: A Non-precious Metal Catalyst for Semi-hydrogenation of Alkynes. Adv. Mater. 2016, 28, 4747−4754. (c) Liang, H. J.; Zhang, B.; Ge, H. B.; Gu, X. M.; Zhang, S. F.; Qin, Y. Porous TiO2/Pt/TiO2 Sandwich Catalyst for Highly Selective Semihydrogenation of Alkyne to Olefin. ACS Catal. 2017, 7, 6567−6572. (36) (a) Mitsudome, T.; Urayama, T.; Yamazaki, K.; Maehara, Y.; Yamasaki, J.; Gohara, K.; Maeno, Z.; Mizugaki, T.; Jitsukawa, K.; Kaneda, K. Design of Core-Pd/Shell-Ag Nanocomposite Catalyst for Selective Semihydrogenation of Alkynes. ACS Catal. 2016, 6, 666− 676. (b) Song, S. Y.; Li, K.; Pan, J.; Wang, F.; Li, J. Q.; Feng, J.; Yao, S.; Ge, X.; Wang, X.; Zhang, J. H. Achieving the Trade-off Between Selectivity and Activity in Semihydrogenation of Alkynes by Fabrication of (Asymmetrical Pd@Ag core)@(CeO2 shell) NanoH


Ultralow-Content Palladium Dispersed in Covalent Organic

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