New hydroformylation catalyst developed - Chemical & Engineering

ACS Chem. Eng. News Archives ... A common problem with some homogeneous catalyst systems is the difficulty of recovering the catalyst. Currently, many...
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man Resources & Intergovernmental panies, especially if the research was Relations Subcommittee of the House federally funded." (About 80% of Committee on Government Opera- MIT's $300 million a year in funds tions, chaired by New York Demo- for on-campus research comes from crat, Ted Weiss. The same subcom- federal sources.) mittee last September aired some "I resent the statement that we examples of misconduct in research sell the results of federally sponthat arose w h e n biomedical re- sored research," Gray responded, searchers had a financial stake in downplaying the benefits of ILP products they were studying. membership. He claims that nonThe panel last week directed most member firms have access to the of its attention to "whether univer- same information if "they scratch sities selling the results of federally for it." funded scientific research to private Subcommittee members seemed industry, including foreign corpo- skeptical that corporations are payrations, is in the public interest/' as ing $50,000 annually for little or no Weiss put it. return. "Our function is to make Under fire was MIT's 40-year-old certain American taxpayers' funds industrial liaison program (ILP), con- are used to the benefit of the Amersidered a model for most other uni- ican public," Weiss said, suggesting versity research interactions with in- that funding agencies need to have dustry. Companies that join the pro- policies against the results of regram for annual fees, ranging from search being sold before publication. Pamela Zurer $10,000 to $50,000, receive what Gray described as "facilitated access" to MIT research. Almost 300 firms, about half foreign and 57 of those Japanese, are currently members of the ILP. Representatives of member companies—each of which is assigned a A new type of catalyst with signifispecial university liaison officer— cant advantages over existing catacan visit MIT faculty and research lysts for commercially important staff, attend conferences, and receive hydroformylation reactions has been research findings that have not yet developed at Virginia Polytechnic appeared in the scientific literature. Institute. In addition, MIT faculty are encourIn hydroformylations, olefinic aged to interact with ILP member compounds react to form aldehydes, firms and are financially rewarded which can then be reduced to genfor phone conversations, company erate alcohols. The system was devisits, and other such contacts. veloped by Mark E. Davis of the Such u n i v e r s i t y / i n d u s t r y pro- department of chemical engineergrams raise several areas of con- ing and Brian E. Hanson of the cern, Princeton University sociolo- chemistry department, with support gist Patricia K. Woolf told the pan- from the National Science Foundael. Foreign corporations can get the tion. benefits of research supported by The new system, supported aqueU.S. taxpayers, perhaps gaining a ous-phase catalysis (SAPC), uses orcompetitive advantage over Ameri- ganometallic catalysts that are discan industry, she said. And Ameri- solved in an aqueous film on the can companies are charged twice surface of a hydrophilic solid supfor access to scientific and technical port. The film is in contact with an information, she pointed out—once organic phase containing the reacas taxpayers and again to join such tants. Heterogeneous catalysis ocprograms. curs within the pores of the supMoreover small companies that port at the aqueous/organic interface. cannot afford to join are put at a A common problem with some disadvantage, Woolf said. "I cannot homogeneous catalyst systems is the see any reason why they should difficulty of recovering the catalyst. not be able to see all of the pre- Currently, many commercial hydroprints, reports, and working papers formylations use homogeneous catthat are available to affiliated com- alysts, which are difficult to recov-

New hydroformylation catalyst developed

er because they are mixed with reactants and products in the organic phase. SAPC catalysts are immobilized on the support material and insoluble in organic media, making it possible to recover the catalysts economically. Hydroformylation catalysts are frequently based on precious metals and are often very expensive. SAPC catalysts are made by coating a high-surface-area solid support, such as silica, with a watersoluble, metal-organic complex. The water phase is then evaporated, leaving the complex distributed over the surface of the support. Water films are then condensed from the vapor phase on the surface of the support in a highly controlled manner. The catalyst support surface is thus coated with a water film containing the catalyst complexes. The film is thin enough to keep a significant number of pores in the support open and accessible. Since the support is hydrophilic, it preferentially retains the aqueous phase. The reactions take place at the interface between the phases and, thus, are highly diffusion-controlled. In addition to immobilizing the catalysts, the SAPC systems provide a large interfacial area because of the porous character of the supports. Another advantage claimed by the developers is the possibility of selectivity and equilibrium variations at the surface over the values in bulk phase. A variety of hydroformylation reactions have been performed with SAPC catalysts, the first b e i n g hydroformylation of oleyl alcohol to aldehydes. Great pains were taken to determine that a catalyst was indeed required for the reaction, to study the function of the aqueous/ organic interface, and to test for effective transport of products and reactants in the organic phase. The organic phase in this reaction was cyclohexane. Current work includes investigating how interfacial effects affect the orientation of molecules at the surface. The geometrical arrangement of molecules at the surface can alter reaction rates, equilibrium, and selectivity. Examples of such reactions are emulsion polymerization and the hydrolysis of fats. Joseph Haggin June 19, 1989 C&EN

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