Improved Ethanol Adsorption Capacity and Coefficient of Performance

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Improved Ethanol Adsorption Capacity and Coefficient of Performance for Adsorption Chillers of Cu-BTC@GO Composite Prepared by Rapid Room Temperature Synthesis Jian Yan, Ying Yu, Jing Xiao, Yingwei Li, and Zhong Li Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.6b03139 • Publication Date (Web): 27 Oct 2016 Downloaded from http://pubs.acs.org on October 30, 2016

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Industrial & Engineering Chemistry Research

Improved Ethanol Adsorption Capacity and Coefficient of Performance for Adsorption Chillers of Cu-BTC@GO Composite Prepared by Rapid Room Temperature Synthesis Jian Yana, Ying Yub, Jing Xiaob*, Yingwei Lia, Zhong Lia* a

School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China

b

Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the

Ministry of Education, South China University of Technology, Guangzhou 510640, PR China Corresponding authors： a. Zhong Li*, Fax: +86 020 87110608(O) E-mail: [email protected] b. Jing Xiao*, Fax: +86 20 87113513(O) E-mail: [email protected]

Abstract A composite of Cu-BTC and graphite oxide (GO) was prepared by rapid room-temperature synthesis method for thermally driven adsorption chillers (TDCs). A series of composites Cu-BTC@GO with varied GO loading were synthesized at room temperature within 1 min, and characterized by N2 adsorption test, SEM, PXRD and FTIR analysis. The adsorption isotherms of ethanol on the composites were measured at different temperatures and then the isosteric heats of ethanol adsorption were estimated. The composite working capacities and coefficient of performance (COP) of the composite-ethanol working pair were calculated for the application of refrigeration. Results showed that Cu-BTC@GO possessed a super-high adsorption capacity for ethanol up to 13.60 mmol/g at 303 K, which was attributed to

ACS Paragon Plus Environment


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introduction of GO leading to increases in the surface dispersive forces and the mesoporous volume of Cu-BTC@GO. The isosteric heat of ethanol adsorption on Cu-BTC@GO was slightly higher than that of Cu-BTC. The adsorption capacity of Cu-BTC@GO was higher than many other MOFs under the application conditions of TDCs. The composites exhibited 5.8~17.4% higher working capacity and energy efficiency than parent Cu-BTC for the application of refrigeration. The rapid room-temperature synthesis approach is potential for preparation of new MOF-based composites. Keywords: Rapid synthesis; Ethanol adsorption; Cu-BTC; Graphite oxide; Adsorption chiller

Introduction Nowadays an intense attention is focused on the global climate change and the energy consumption rising. The energy for households worldwide is responsible for about one third of the world’s consumption of energy, primarily for heating and cooling 1. Therefore a great amounts of researches have been done to mitigate primary energy requirements for heating and cooling, and the thermally driven adsorption chillers (TDCs) (or adsorption heat pumps, AHPs) 2-10 is one of the hottest topics. The TDCs system which based on reversible adsorption/desorption cycle of a refrigerating fluid on an adsorbent is a promising method for cooling with sustainably utilization of natural and low-grade thermal such as solar energy

11

and waste heat 7. Efficient


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working pairs consisting of porous solid adsorbent and working fluid refrigerant are the most important parts in the system of TDCs. To date, there are various refrigerants to choose, such as water, ethanol, methanol, and ammonia etc.

6, 12, 13

. Among them,

methanol and ammonia are limited for their toxicity. Water stands out as its high latent heat and harmlessness 8, but its drawback is that it needs to work at very low (vapor) pressures and subzero temperatures cannot be achieved 9. Comparing with the working fluids above, ethanol is considered as an ideal refrigerant for its good latent heat, high thermal stability, environmentally benign property, and more importantly, it can work at subzero temperature. Besides, a novel adsorbent with excellent performance of adsorption/desorption plays a key role in the system of TDCs. Traditional adsorbents, activated carbon was one of the most-studied materials as ethanol adsorbent

14-17

. LeVan et al.

17

measured

adsorption isothermals for ethanol on BPL activated carbon, and reported that its ethanol adsorption capacity was ~8 mmol/g. The ethanol uptakes of RX3 15 activated carbon and BAC

14

were also tested, and in the range of 6.9~7.6 mmol/g.

El-Sharkawy et al. 16 investigated Maxsorb III activated carbon–ethanol pair for solar powered adsorption cooling applications, and reported that Maxsorb III possessed super-high ethanol uptake of 26 mmol/g, having potential for application of TDCs system. Therefore, design and development novel adsorbents with superior ethanol adsorption performance is crucial to enhance the performance of TDCs system when using ethanol as refrigerant.



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In recent years, Metal−organic frameworks (MOFs) have shown great potential in the adsorption chiller for its exceptional high porosity and large surface area 4, 13, 18. Rezk et al.

13

investigated the performance of MIL-101(Cr) as ethanol adsorbent in

TDCs system, and reported that its ethanol adsorption capacity was up to 1.2 g/g. Kapteijn group

9

investigated ethanol adsorption performances of 18 MOFs, and

reported that the ethanol capacity and COP of CAU-3 were up to 0.6 g/g and 0.7 separately in the application of refrigeration, which makes CAU-3 very suitable to work with ethanol in TDCs system. Although MOFs have ultrahigh specific area, their low density of atoms in the structure cannot provide dispersive forces strong enough to bind small molecules at ambient conditions 19, 20. In other words, the adsorption performance of MOFs can be still further improved if its atomic density was further enhanced. For example, combining dense carbon substrates with MOFs can prepare composites with excellent adsorption performances. These carbon substrates include functionalized graphite 21, 22, graphite oxide (GO)

23, 24

, carbon nanotubes

25

and activated carbon 26 , of which GO

showed great potential since it contains functional group (carboxylate or hydroxyl groups) on the graphene plane. GO could provide the coordination sites for metal ions and thus guide the growth of MOFs including MOF-5@GO

28

27

. At present, several MOF@GO composites

, MIL-101(Cr)@GO

29, 30

and Cu-BTC@GO

19

were

synthesized. It was reported that the incorporating of GO into MOFs structures would noticeably improve the adsorption performances of the composites for adsorption of


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CO2, H2O and VOCs 23, 29, 30. Nevertheless, most of the MOF@GO composites were prepared by traditional solvothermal methods, which need long synthesis time and high react temperature. A fast and low energy consuming synthetic method is highly desired for commercially production of MOF@GO. Li et al.

31

proposed a solvent-free mechanochemical

method to synthesize of Cu-BTC@GO within 30 min successfully, and the resultant Cu-BTC@GO exhibited a higher toluene uptake compared to parent Cu-BTC. Although the mechanochemical method can reduce the synthesis time and temperature required for MOF preparation, but extra energy input are still needed to drive the chemical reaction. Therefore, it is desirable to seek for a more gentle and efficient method for the synthesis of MOF@GO composites. Recently, some metal oxides (e.g. ZnO) and hydroxides have been reported to act as efficient nucleating agents or sources of cations for rapid synthesis of MOFs Zhao et al.

34

32, 33

.

reported a rapid room-temperature synthesis method using (Zn, Cu)

hydroxyl double salts (HDSs) as intermediates for preparation of HKUST-1 (Cu3(BTC)2). Synthesis of HKUST-1 can be finished within few minutes at room temperature, showing great potential for efficient preparation of MOFs. This rapid room-temperature synthesis is worthy of further developing. In this work, a rapid room-temperature synthesis was proposed to prepare the composites of Cu-BTC and GO. The prepared composites Cu-BTC@GO were



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characterized by N2 adsorption, SEM, XRD and FTIR analysis. Ethanol adsorption isotherms of Cu-BTC@GO and Cu-BTC were measured. Ethanol adsorption capacities of Cu-BTC@GO at working pressures and temperatures were separately estimated for ice making and refrigeration, and the coefficient of performance (COP) of the composite-ethanol pairs for TDCs was calculated and compared for the applications of adsorption chillers.

1. Experiments 1.1 Synthesis of Cu-BTC@GO by rapid room temperature approach

Firstly, GO was synthesized via the Hummers method

35

, and then GO was

dispersed in 8 mL of deionized water for 2 h. After that, 1.74 g of Cu(NO3)2·3H2O was added in the above solution and the resultant solution was sonicated for 20 min. At the same time, 0.293 g of ZnO powder was dispersed in 8 mL of deionized water and sonicated for 10 min to form ZnO nanoslurry. 0.84 g H3BTC was dissolved in 16 mL of ethanol in another beaker. Thirdly, the ZnO nanoslurry was added into 16 mL of DMF under stirring, then GO/Cu(NO3)2 solvent mixture was added and next the H3BTC solution. After 1 min, blue particles was appeared. Finally the obtained product was filtered and washed with 50 mL ethanol for three times and dried at 120℃ for 6 hours in vacuum oven to obtain the Cu-BTC@GO composites. The composites were referred to Cu-BTC@GO-n, while n=1, 2, 3, 5 and 10 represent the 1, 2, 3, 5 and 10 wt% of GO of the initial weight of Cu(NO3)2·3H2O and H3BTC,


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respectively.

1.2 Material characterization

N2 physisorption were performed at 77 K using an ASAP 2020 porosity analyzer (Micromeritics). The specific surface area and pore volume can be calculated by an equipped commercial software of analysis. Scanning electron microscope images were taken on a Philips FEIXL-30 electron microscope at accelerating voltage of 10 kV. Powder X-ray diffraction (PXRD) patterns of the materials were obtained using a D/max-IIIA diffractometer at 35 kV and 25 mA and analyzed by using Cu-Kα radiation. The surface organic FTIR spectra were measured by Bruker 550 FTIR instrument with a resolution of 4 cm-1. The collected spectra was range from 400 to 4000 cm-1, with a resolution of 4 cm-1.

1.3 Ethanol adsorption measurements.

The ethanol adsorption isotherms at different temperatures were measured with a high-resolution Micromeritics 3-Flex adsorption instrument equipped with a stainless steel vapor vessel. Before the adsorption measurements, the vessel was filled with ethanol (~20 mL) and vacuum was applied to remove residual gases in the gas path of the instrument. Then keep the vessel at 40℃ to form ethanol vapor. The initial outgassing process for the samples were carried out at 423 K for 8 h under vacuum.



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1.4 Operation cycle of thermally driven adsorption chillers (TDCs) system.

Figure 1 shows an operation cycle of TDCs system. A TDCs system is mainly composed of an evaporator/condenser containing working fluid such as ethanol and an adsorbent tank packed with adsorbents. The adsorption cooling cycle can be described in three stages. Adsorption and evaporation: the ethanol vapor from evaporator is adsorbed by adsorbents packed in adsorption tank, and at the same time the ethanol is continually evaporated until the adsorbents get saturated. When liquid ethanol evaporates in a low partial pressure environment, it results in extracting heat from its surroundings (e.g. the space to be cooled). Because of the low partial pressure, the temperature needed for ethanol evaporation is also low. Regeneration: The ethanol-saturated adsorbents needs regenerating for cycle use, and thus are heated by a low-grade heat source such as waste heat and solar energy, causing the ethanol to desorb and evaporate out. The hot ethanol vapor passes through a heat exchanger/ condenser, transferring its heat outside the system (such as to surrounding ambient-temperature air), and thus condenses into liquid ethanol. The condensed (liquid) ethanol enters into evaporator and supplies the evaporation phase for next cycle. The principle of operation cycle of TDCs system has been described in detail elsewhere 6. For a given working pair, the operational conditions of TDCs system are fully


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fixed when the temperature of evaporator (Tev), adsorbent (Tads) and desorption (Td) are chosen 6, 9. The employed operational temperatures in this work were provided in supporting information (Table S1).

Figure 1. Illustration of principle of operation cycle for TDCs.

2. Results and discussion 2.1 Physical Characteristics.

Figure 2. PXRD pattern of the composites and Cu-BTC.



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Figure 2 presents the PXRD patterns of Cu-BTC and Cu-BTC@GO composites. The PXRD pattern of Cu-BTC was in agreement with those reported elsewhere

36

. The PXRD spectrum of Cu-BTC@GO largely resembled that of

Cu-BTC, indicating that the graphitic components did not disturb the crystallization of Cu-BTC structures. This result was inconsistent with other MOFs@GO composites reported before

29, 37

. It was noticed that the peak at

2θ∼6.7° and 9.5° became weaker when GO content increased to 3%, which might be related to an increase in the distortion of Cu-BTC structure owing to the excessive addition of GO 30, 38.

Figure 3. N2 isotherms of the composites and Cu-BTC. Figure 3 presents N2 isotherms of the samples. It was found that the N2 isotherms of these composites were lower than that of Cu-BTC, suggesting the decreased specific surface area of the composites. However, it was worthy of noting that the hysteresis loops from N2 isotherms became bigger as the content of GO increased, which indicated that the mesoporosity of the composite was


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enhanced. Table 1 shows the textural parameters of the samples studied. The specific surface area of the composites were decreased compared to parent Cu-BTC. The reason might be that there were additional constraints on the degrees of freedom caused by the introduction of GO for the growth of the Cu-BTC crystals during the synthesis of the composite

39, 40

. It was also found that the total pore volume and

mesopore volume of the composites were increased with the content of GO (< 2%) and then reached the maximum value. After that, it decreased when the content of GO was above 3%. The result suggested the formation of new mesopores, which could be attributed to the hybridization of MOFs crystals and GO 38, 41. Table 1 Porous textural parameters of Cu-BTC and the composites with different GO content. Sample

Surface area (m2/g)

Pore volume (cm3/g)

BET

Langmuir

total

meso

micro

Cu-BTC

1478

1953

0.701

0.089

0.584

Cu-BTC @GO-1

1452

1918

0.731

0.127

0.579

Cu-BTC @GO-2

1459

1930

0.789

0.169

0.573

Cu-BTC @GO-3

1428

1887

0.703

0.138

0.561

Cu-BTC @GO-5

1327

1754

0.656

0.115

0.516

Cu-BTC @GO-10

1274

1689

0.663

0.114

0.479

Figure 4 shows SEM images of Cu-BTC and Cu-BTC@GO composites with varied GO contents. Cu-BTC crystallized product exhibited a clear octahedral morphology. For the composites, Cu-BTC particles kept the octahedral morphology and packed inside the amorphous GO which exhibited a dense silk like as the disordered arrangement of graphene layers stacking together. It could



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be found that the heterogeneity became much more obvious as the content of GO increased. Another difference was that the sizes of the composite crystals were in the range of 0.8~1 µm, approximately 0.2~0.3 times as the size of Cu-BTC. The reason might be ascribed to the existence of additional constraints in the degrees of freedom for the growth of Cu-BTC crystals during the synthesis of the composites caused by the presence of GO 30.

Figure 4. SEM images of Cu-BTC (A1, A2) and composites Cu-BTC@GO-1 (B1,


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B2), Cu-BTC@GO-2 (C1, C2) and Cu-BTC@GO-3 (D1, D2). The results above confirmed that the Cu-BTC@GO composites have been successfully synthesized by rapid room-temperature synthesis method. In this procedure, hydroxyl double salt (HDS) intermediate showed excellent anion exchangeability 18 played the crucial role. HDSs are a class of layered materials which consisting of cationic sheets connected by inorganic/organic interlamellar anions

17

.

Generally, HDSs formed by reacting one divalent metal oxide MeO with another different divalent metal ions M2+. For example, ZnO can react with different divalent cations such as Co2+, Ni2+ and Cu2+ salts, CuO can react with Co2+ and Ni2+, Zn2+, Mg2+ to form HDS

17

. In this work, (Zn, Cu) hydroxy nitrate HDS were synthesized

by reacting ZnO with Cu2+ salt. The successful synthesis of Cu-BTC@GO suggested that this synthesis method is not limited to form bulk MOF powder but also applicable for MOFs@GO.

2.2 Adsorption isotherms of ethanol on the composites.



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Figure 5. Ethanol adsorption isotherms of the Cu-BTC@GO composites (303 K). Figure 5 presents the isotherm of ethanol on the Cu-BTC@GO composites with different GO contents. All of the isotherms showed a two-step adsorption behavior. The two-step uptake corresponds to the sequentially filling of the cages of different size in Cu-BTC

18

. The composites exhibited significantly higher ethanol adsorption

capacity than parent Cu-BTC, of which Cu-BTC@GO-2 showed a very high ethanol capacity of 13.60 mmol/g, much higher than that of Cu-BTC (11.68 mmol/g)

13, 18

,

which was attributed to introduction of GO leading to increases in the surface dispersive forces and the mesoporous volume of Cu-BTC@GO. It was observed that the ethanol adsorption capacities of the composites increased with the content of GO loading, and then reached maximum when increased (< 2%). After that, it decreased as the GO content further increased (> 3%). This phenomenon could be explained by the changed pore volume of the samples. It was worthy of noting that the saturation ethanol capacity of the samples were rather close to the pore volumes determined with N2 (Table 2), suggested that the pores of materials were nearly fully saturated with the ethanol. Table 2 Ethanol capacities and pore volumes of the Cu-BTC@GO composites Material

Pore vol (cm3/g)

Qads (cm3/g)

Cu-BTC

0.701

0.689

Cu-BTC@GO-1

0.731

0.735

Cu-BTC@GO-2

0.789

0.799

Cu-BTC@GO-3

0.703

0.684

Cu-BTC@GO-5

0.656

0.649


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Cu-BTC@GO-10

0.663

0.642

2.3 Isosteric heat of ethanol adsorption on the composites

The isosteric heat of adsorption (∆Hs) is an important parameter to evaluate the interaction ethanol with adsorbent surfaces and calculate the COPs of the working pairs in TDCs system. According to ethanol isotherms measured at different temperatures, the ∆Hs can be calculated from the following Clausius-Clapeyron equation 42: ln p = −

∆H S +C RT

(1)

Where p (Pa) is the ethanol feed pressure, ∆Hs (kJ/mol) is the isosteric heat of ethanol, R (kJ/mol·K) is the ideal gas constant, T (K) is the adsorption temperature, and C is an integration constant.

∆Hs can be estimated based on the obtained ethanol isotherms at different temperatures (See Figure S2 in Supporting Information). The isosteric enthalpy of adsorption, as a function of loading, was shown in Figure 6. It was observed that the isosteric heat of ethanol adsorption on both Cu-BTC and Cu-BTC@GO-2 decreased with ethanol uptakes. At low surface coverage of ethanol, ethanol molecules and unsaturated Cu ion sites interacted strongly. As surface loading increased, ethanol molecules began to adsorb in the micropores of the samples, and thus the ∆Hs decreased. Additionally, the ∆Hs of ethanol adsorption on Cu-BTC@GO-2 was in the



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range of 45~59 kJ/mol which was slightly higher than that of Cu-BTC. It might be attributed to the introduction of GO resulting in enhancement of the surface dispersive forces Cu-BTC@GO-2.

Fig. 6 Isosteric enthalpy of ethanol adsorption on Cu-BTC@GO-2 and Cu-BTC.

2.4 COP of the composite-ethanol pairs for TDCs.

In the actual application of adsorption chiller, the adsorption-desorption cycles of ethanol on an adsorbent are operated in a close adsorption system. Thus, its operation pressures (relative pressure, P/P0) of the adsorption step are generally limited in the range of 0.10~0.25

2, 4, 43, 44

when ethanol was used as refrigerant. Hence, the ethanol

uptakes in the range of P/P0 (working pressure) are usually applied to evaluate the performance of different adsorbent-ethanol pairs for adsorption chiller. In order to compare the performance of different adsorbents reasonably, Kapteijn group

6

proposed an operation temperature criterion in which 2 typical operating temperatures for adsorption cooling applications such as refrigeration (Tev=278 K, Tads=303 K) and


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ice making (Tev=268 K, Tads=298 K), which had widely been accepted 2, 43, 45. According to the typically operation temperatures mentioned above, the corresponding P/P0 of the each adsorption steps were calculated to be 0.21 for refrigeration and 0.14 for ice making

46, 47

, respectively. Thus, the adsorption

capacities of an adsorbent at working relative pressures P/P0 of 0.14 and 0.21 can be separately obtained on the basis of an adsorption isotherm. For comparison, Figure S4 presents the ethanol adsorption isothermals of Cu-BTC, Cu-BTC@GO and some MOFs such as MIL-101 (Cr) 13, MIL-53 13, ZIF-67 9

, ZIF-8 9, MIL-140c

9

at 298 K and MIL-100(Fe)

48

at 303 K. It was clearly visible

that ethanol adsorption capacity at low pressure P/P0 < 0.15 of Cu-BTC@GO was significantly higher than those of these MOFs. Figure 7 presents the ethanol adsorption capacities of the materials at working relative pressure P/P0 of 0.14 and 0.21. It showed that Cu-BTC@GO-2 had the highest ethanol uptake among the selected materials at P/P0 of 0.14 for ice making. In addition, Cu-BTC@GO-2 also exhibited the highest ethanol uptake among the selected materials except MIL-101(Cr) at P/P0 of 0.21 for refrigeration. It implied that Cu-BTC@GO-2 possessed excellent ethanol adsorption performance, which would be a promising adsorbent for adsorption chillers.



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Figure 7. Ethanol adsorption capacities of Cu-BTC@GO and some MOFs at working pressure P/P0 of 0.14 and 0.21. Coefficient of performance (COP) was the most important parameter to assess the energy efficiency of working pairs in TDCs system. COP is defined as the useful energy output divided by the energy required as input 2, 6, 18, and it could be calculated according to the equation (2) for adsorption refrigeration.

COPc =

Qev Qregen

（2）

Here, Qev is the energy taken up in the evaporator (kJ). Qev can be calculated with knowledge of the enthalpy of evaporation ∆vapH according to the equation (3).

Qev = ∆ vap H ⋅ msorbent ⋅ ∆W ⋅ M wf

（3）

Here, msorbent is the amount of adsorbent used in the adsorption refrigeration. ∆W is the working capacity and Mwf is the molar mass of the working fluid. △W is


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defined as the difference between ethanol adsorption capacities of an adsorbent under the condition of adsorption and desorption, a net ethanol adsorption capacity. Qregen is the energy required for the regeneration of the adsorbent (kJ). Qregen can be calculated from the Td and ∆Hs (See S4 in supporting information). Figure 8a presents the △W of Cu-BTC@GO-ethanol and Cu-BTC-ethanol pairs for adsorption refrigeration. The △W of the two samples increased gradually with Td and reach the maximum of 4.2~4.6 mmol/g at 388 K, which was attributed to desorption of more ethanol at higher Td. It was noteworthy that the △ W of Cu-BTC@GO-2 was higher than that of Cu-BTC, having an increase of 6.1~17.4% compared to Cu-BTC at desorption temperatures above 370 K. It was mainly ascribed to higher ethanol uptake of Cu-BTC@GO-2 at low relative pressure compared to Cu-BTC, as shown in Figure 5. Figure 8b shows the COP of Cu-BTC@GO-ethanol and Cu-BTC-ethanol pairs. The COP of Cu-BTC@GO-2-ethanol working pairs was higher than that of Cu-BTC-ethanol working pairs, suggesting that the composite is more efficient than Cu-BTC. It was mainly attributed to higher working adsorption capacity of Cu-BTC@GO-2 resulting in higher Qev and COP. In addition, it was observed that the COP of Cu-BTC@GO-2-ethanol working pairs increased with Td increased, and reached of 0.54 at about 370 K. After that, it slightly increased or nearly maintained constant with increasing temperature until Td < 390 K. This was because the further elevating desorption temperature could release more ethanol, and meanwhile, it also



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resulted in more consumption of energy.

Fig. 8a Working adsorption capacity ∆W of the two samples as function of desorption temperature Td under refrigeration condition

Fig. 8b COPc of two working pairs as function of desorption temperature, Td, under refrigeration condition

Conclusions In this work, the composites of Cu-BTC@GO were successfully prepared by rapid room-temperature synthesis method for thermally driven adsorption chillers (TDCs). The synthesis of Cu-BTC@GO can be finished within 1 min under room temperature. The resultant Cu-BTC@GO exhibited higher mesoporous volume than Cu-BTC. The ethanol adsorption capacity of Cu-BTC@GO was up to 13.60 mmol/g at 303 K, which was 16% higher in comparison with the parent Cu-BTC. The isosteric heat of ethanol adsorption on Cu-BTC@GO was in the range of 45~59 kJ/mol, slightly higher than that on Cu-BTC. The composites Cu-BTC@GO exhibited excellent adsorption performance as an adsorbent for the application of adsorption chillers. Its ethanol adsorption capacity was higher than many other MOFs including Cu-BTC,


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MIL-101, MIL-53 and so on under the application conditions of TDCs. In addition, it exhibited 5.8~17.4% higher working capacities and COP compared to the parent Cu-BTC for the application of refrigeration. Besides, the rapid room-temperature synthesis method is suitable for preparation of MOF-based composites for TDCs.

Acknowledgements

This work was supported by National Key Basic Research Program of China (2013CB733506), National Natural Science Foundation of China (No. 51276065), the Research Foundation of State Key Lab of Subtropical Building Science of China (C713001z), and the Fundamental Research Funds for the Central Universities (No. 21436005).

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TOC 150x100mm (150 x 150 DPI)


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Improved Ethanol Adsorption Capacity and Coefficient of Performance

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