Catalysis research

The research for this thesis was carried out in connection with NIOK, the Netherlands Institute for Catalysis Research and supported by the Department of Economic Affairs. 

Meisel, S. L. Catalysis Research Bears Fruit, CHEMTECH, January 1988, pp. 32-37. 

Serious research in catalytic reduction of automotive exhaust was begun in 1949 by Eugene Houdry, who developed mufflers for fork lift trucks used in confined spaces such as mines and warehouses (18). One of the supports used was the monolith—porcelain rods covered with films of alumina, on which platinum was deposited. California enacted laws in 1959 and 1960 on air quality and motor vehicle emission standards, which would be operative when at least two devices were developed that could meet the requirements. This gave the impetus for a greater effort in automotive catalysis research (19). Catalyst developments and fleet tests involved the partnership of catalyst manufacturers and muffler manufacturers. Three of these teams were certified by the California Motor Vehicle Pollution Control Board in 1964-65 American Cyanamid and Walker, W. R. Grace and Norris-Thermador, and Universal Oil Products and Arvin. At the same time, Detroit announced that engine modifications by lean carburation and secondary air injection enabled them to meet the California standard without the use of catalysts. This then delayed the use of catalysts in automobiles. 

We have witnessed discussions and participated in panels formed to determine what catalysis research is most relevant. It occurred to us that never once did anyone ask (let alone answer) the question relevant to whatl Surely, how could we expect meaningful conclusions without agreeing on a common premise ... 

By 19884 it became obvious that the NEMCA effect, this large apparent violation of Faraday s law, is a general phenomenon not limited to a few oxidation reactions on Ag. Of key importance in understanding NEMCA came the observation that NEMCA is accompanied by potential-controlled variation in the catalyst work function.6 Its importance was soon recognized by leading electrochemists, surface scientists and catalysis researchers. Today the NEMCA effect has been studied already for more than 60 catalytic systems and does not seem to be limited to any specific type of catalytic reaction, metal catalyst or solid electrolyte, particularly in view of... 

Discuss strategies for devising model systems of catalysts that allow surface science methods to be applied in catalysis research. 

The 138 submitted papers were selected in the following marmer. From a total of 521 submitted two-page abstracts, 156 were identified by peer review and evaluation of the Program Committee to be expanded into 10-page (maximum) camera-ready manuscripts. Submitted manuscripts were then peer-reviewed by at least two experts in the field according to standards comparable to those used for archival journals. Diversity in country origin was also considered, and an attempt was made to minimize multiple publications for individual research groups. Consequently, the 138 papers included herein should be considered as peer-reviewed publications that represent the worldwide state-of-the-art in catalysis research. 

Zech, T, Schunk, S., Klein, J., Demuth, D., The integrated materials chip for high-throughput experimentation in catalysis research, in Proceedings of the 6th International Conference on Microreaction Technology, IMRET 6, pp. 32-36 (11-14 March 2002), AIChE Pub. No. 164, New Orleans. 

Attempts to determine how the activity of the catalyst (or the selectivity which is, in a rough approximation, the ratio of reaction rates) depends upon the metal particle size have been undertaken for many decades. In 1962, one of the most important figures in catalysis research, M. Boudart, proposed a definition for structure sensitivity [4,5]. A heterogeneously catalyzed reaction is considered to be structure sensitive if its rate, referred to the number of active sites and, thus, expressed as turnover-frequency (TOF), depends on the particle size of the active component or a specific crystallographic orientation of the exposed catalyst surface. Boudart later expanded this model proposing that structure sensitivity is related to the number of (metal surface) atoms to which a crucial reaction intermediate is bound [6]. 

Catalysis Research Center, Hokkaido University, Sapporo, Japan Japan Science and Technology Agency, Kawaguchi, Japan... 

Characterization is essential in catalysis research and development. Catalysts are complex entities, and therefore, it is not surprising that catalyst characterization is a broad subject. The crucial information that is needed can be summarized as ... 

For most catalysts, mesopores are dominant, whereas for materials derived from zeolites or active carbons, micropores are the most important. Determination of the pore size distribution is indispensable in catalysis research. 

In 1993, ten challenges faced the catalysis research community. One of these was the anti-Markovnikov addition of water or ammonia to olefins to directly synthesize primary alcohols or amines [323]. Despite some progress, the direct addition of N-H bonds across unsaturated C-C bonds, an apparently simple reaction, stiU remains a challenging fundamental and economic task for the coming century. 

Environmental Catalysis Research Group, Universidad de Antioquia-CENIVAM,... 

For similar motivations, there are limited incentives to develop an alternative SCR process for stationary sources based on methane (CH4-SCR) or other HCs, or based on NTP technologies, if not for specific, better applications. The situation is instead quite different for mobile sources, and in particular for diesel engine emissions. The catalytic removal of NO under lean conditions, e.g. when 02 during the combustion is in excess with respect to the stoichiometric one (diesel and lean-burn engines, natural gas or LPG-powered engines), is still a relevant target in catalysis research and an open problem to meet future exhaust emission regulations. 

Kubanek, P., Busch, O., Thomson, S. et al. (2004) Imaging reflection IR spectroscopy as a tool to achieve higher integration for high-throughput experimentation in catalysis research. J. Comb. Chem., 6, 420. 

One of the exciting results to come out of heterogeneous catalysis research since the early 1980s is the discovery and development of catalysts that employ hydrogen peroxide to selectively oxidize organic compounds at low temperatures in the liquid phase. These catalysts are based on titanium, and the important discovery was a way to isolate titanium in framework locations of the inner cavities of zeolites (molecular sieves). Thus, mild oxidations may be run in water or water-soluble solvents. Practicing organic chemists now have a way to catalytically oxidize benzene to phenols alkanes to alcohols and ketones primary alcohols to aldehydes, acids, esters, and acetals secondary alcohols to ketones primary amines to oximes secondary amines to hydroxyl-amines and tertiary amines to amine oxides. 

III. Some Heat-Flow Microcalorimeters That Can Be Used in Heterogeneous Catalysis Research. 196... 

The lack of calorimetric data is particularly evident in the case of the adsorption of gases on oxides or on oxide-supported metals, i.e., on solids similar to most industrial catalysts. Moreover, adsorption calorimeters are generally used at temperatures that are much lower than those usually found in industry, and it would be difficult indeed to adapt most usual adsorption calorimeters for the measurement of heats of adsorption of gases on industrial catalysts at elevated temperatures. The present success of gas chromatographic techniques for determining heats of reversible adsorption may be explained by the gap between the possibilities of the usual adsorption calorimeters and the requirements of industrial catalysis research. 

A survey of the literature shows that although very different calorimeters or microcalorimeters have been used for measuring heats of adsorption, most of them were of the adiabatic type, only a few were isothermal, and until recently (14, 15), none were typical heat-flow calorimeters. This results probably from the fact that heat-flow calorimetry was developed more recently than isothermal or adiabatic calorimetry (16, 17). We believe, however, from our experience, that heat-flow calorimeters present, for the measurement of heats of adsorption, qualities and advantages which are not met by other calorimeters. Without entering, at this point, upon a discussion of the respective merits of different adsorption calorimeters, let us indicate briefly that heat-flow calorimeters are particularly adapted to the investigation (1) of slow adsorption or reaction processes, (2) at moderate or high temperatures, and (3) on solids which present a poor thermal diffusivity. Heat-flow calorimetry appears thus to allow the study of adsorption or reaction processes which cannot be studied conveniently with the usual adiabatic or pseudoadiabatic, adsorption calorimeters. In this respect, heat-flow calorimetry should be considered, actually, as a new tool in adsorption and heterogeneous catalysis research. 

Moreover, the use of heat-flow calorimetry in heterogeneous catalysis research is not limited to the measurement of differential heats of adsorption. Surface interactions between adsorbed species or between gases and adsorbed species, similar to the interactions which either constitute some of the steps of the reaction mechanisms or produce, during the catalytic reaction, the inhibition of the catalyst, may also be studied by this experimental technique. The calorimetric results, compared to thermodynamic data in thermochemical cycles, yield, in the favorable cases, useful information concerning the most probable reaction mechanisms or the fraction of the energy spectrum of surface sites which is really active during the catalytic reaction. Some of the conclusions of these investigations may be controlled directly by the calorimetric studies of the catalytic reaction itself. 

This chapter illustrates that the potential of scC02 for reaction engineering of homogeneous catalysis offers a great scope for possible scientific and technical innovation. This newly emerging field of catalysis research lies at the interface of molecular sciences and process engineering and its future development will require truly interdisciplinary efforts from experts in both fields. 

Carefully determined conversion-time diagrams, in-situ spectroscopic studies and, if possible, kinetic time laws belong to the fundamentals of catalysis research and are prerequisites for a mechanistic understanding [8]. 

In a serial mode (Fig. 36.1), one experimental step (in catalysis research this is usually the preparation of the ligand or the catalyst) is repeated n times before moving on to the next step. The only difference with traditional research is that the complete experiment (synfhesis/testing/analysis) is carried out for a set of catalysts rather than for an individual species. For example, a library of ligands from the same class can be assembled via traditional organic synthesis prior to its testing in catalysis. (A library of compounds is a rather large collection of different compounds with some common features and usually the same function, for example triarylphosphines or imidazolidinones.) Ideally, the compounds in the library can be structurally varied in at least two positions to ere-... 

Dr. Yanzhong Li Catalysis Research Centre and Graduate School of Pharmaceutical Sciences Hokkaido University and CREST Sapporo 060811 Japan Dr. Steven S. Pfeiffer Department of Chemistry and Biochemistry University of California Santa Barbara California 93106-9510 USA Dr. Bjorn Rinker... 

Prof. Tamotsu Takahashi Catalysis Research Center and Graduate School of Pharmaceutical Sciences Hokkaido University and CREST Kita-ku... 

Since its publication I have used the book as an accompanying text in courses on catalyst characterization, both at the Eindhoven University of Technology and the Netherlands Institute for Catalysis Research, NIOK. It has been very rewarding to learn that several colleagues in catalysis have adopted the book for their courses as well. I will be very grateful for comments and corrections. Colleagues who are interested in the exercises we use at Eindhoven are most welcome to contact me, the set is available at nominal cost. 

Hokkaido University Catalysis Research Center Kita-ku... 

Lucio Forni (J ), while discussing catalysis research, commented that "Each technique, in fact, taken by itself, allows some useful information to be collected, but can give rise to criticisms. The combination of information obtainable by two or more of them can often be the only way to give a complete picture of the surface acid properties of the solid."... 

---