A catalyst makes a reaction happen. In a process known as catalysis, a relatively small amount of foreign material, called a catalyst, augments the rate of a chemical reaction without being consumed in the reaction. A catalyst can make a reaction go faster and in a more selective manner. Because of its ability to speed up some reactions and not others, a catalyst enables a chemical process to work more efficiently and often with less waste. Hence, catalysts are important in industrial chemistry.
Nancy Jackson, senior member of the technical staff at Sandia National Laboratory, directs catalysis research in the Catalysis and Chemical Technologies department, Energy and Environment sector. Jackson's research is in heterogeneous catalysis-the use of catalysts which are in a separate phase from the reactants. In heterogeneous catalysis, the reactants, which are usually in gaseous or liquid phases, flow through a reactor and sorb onto the surface of a solid catalyst. A reaction takes place, and then the reactants desorb. The reactants are taken downstream for further use, and the catalyst remains unchanged in the process. Jackson says that industry prefers heterogeneous over homogeneous catalysis, in which the catalysts, reactants, and products are usually liquids; it is generally difficult and expensive to separate them.
"Understanding the structure and chemistry of the catalyst surface is essential, because that's where the reaction takes place," says Jackson. Because the reaction takes place on the surface, these materials can work efficiently in small amounts. Joe Miller, senior process research and development chemist at Catalytica, sums up this capability: "One molecule of catalyst can make a million molecules of product. Working with catalysts puts chemistry in a whole new dimension.
The most well-defined areas of industrial catalysis are petroleum, pharmaceutical, and environmental catalysis. Petroleum catalysis employs catalysts to manufacture petrochemicals derived from crude oil. Pharmaceutical catalysis uses catalysts in the manufacture of molecules that have a targeted and very specific function in the body. Environmental catalysis uses catalysts to remove toxic or waste products from manufacturing effluent.
John Steger, director of environmental technology catalysis research and development at Englehard Corporation, has worked in the petrochemical industry developing a new process using catalysis to produce benzene. The process is more selective than traditional benzene production methods and yields fewer unwanted byproducts. Steger says, "It is very satisfying seeing a catalyst we designed produce the high-selectivity levels we anticipated and modeled. The challenge of catalysis is not only trying to understand a process but also realizing a technology that has real value for society.
Miller echoes Steger's sentiment. His area of expertise is using catalysts in the production of therapeutic ingredients for the pharmaceutical industry, and he works on improving methods that drug companies use to make new molecules. "Though some steps in drug manufacturing processes are regulated by the Food and Drug Administration," says Miller, "we can often reduce the number of steps involved in the synthesis of a drug." Such efforts increase the efficiency of the process and promote financial viability for the manufacturer.
Catalytic chemistry is used in many different ways to minimize the impact of industry on the environment. They are often used to treat hazardous materials. When materials passed over the appropriate catalyst, organic or toxic elements can be filtered out. Catalysts are built into manufacturing processes to improve the overall yield. "This is important when it comes to the environment," says Leo Manzer, director of the corporate catalysis center at DuPont. Adding a catalyst can give you 100% yield, no waste, and no environmental problems in the process." Manzer is an organic chemist by training, but he has spent the past ten years of his career working strictly on catalysis research and considers himself a de facto environmental chemist.
Environmental catalysts are also used to reduce emissions from gasoline and diesel engines by using automotive catalytic converters. Using an active metal in a device that provides a large surface area for metal dispersion and intimate contact between exhaust gas and the metal catalyst, a catalytic converter promotes chemical reactions for the conversion of the pollutants into carbon dioxide, water, and nitrogen.
Some large chemical companies have divisions that manufacture their own catalysts. But, for the most part, catalytic chemists in this country work on adapting existing catalysts for their companies' specific needs.
Frank Herkes, a research fellow in Nylon Intermediates at DuPont, studies the basic chemicals and byproducts DuPont makes and finds ways to make new products from them using catalysis. "First, I scout what catalysts exist on the market, seek to tailor them to our needs, and test these catalysts in my lab," he says.
"When choosing a catalyst," says Herkes, "I look at the temperature and pressure requirements, mass transfer of reactants, the weight and size of the catalyst, what degrades it, and what it costs. An understanding of chemical engineering as well as chemistry comes into play when putting a catalytic process together, because costs of raw materials and utilities for running the process need to be considered.
"Steve Curts, a process research chemist at Catalytica, has also worked for a major pharmaceutical manufacturer. He says, "We use traditional chemistry techniques to support process development. There's also a significant amount of fundamental research that is necessary when typical textbook procedures are not transferable to large-scale synthesis projects. That's where industrial experience becomes valuable."
To gain this experience, chemists advise students interested in this field to expose themselves to catalysis and other areas of industrial chemistry. "I would suggest that students take full advantage of industrial internship positions whenever possible," says Curts. Chemists say they have learned most about their field through experience, trial, and error.
Chemists in the field of catalysis have backgrounds in the gamut of chemical career areas and have backgrounds in a variety of areas such as organic chemistry, physical chemistry, solid state chemistry, and surface chemistry. A solid understanding of inorganic chemistry is also necessary since catalysts are often made of metals. An understanding of chemical engineering is helpful because catalysis is tied to the discovery and improvement of chemical processes.
Chemists in this field spend most of their time in the lab carrying out their own work and directing group research. Some time is spent at conferences, industry gatherings, and meetings with business groups and customers who use catalytic processes. Chemists also interface with the industry they serve. For example, chemists making and adapting emissions control catalysts will spend time working with automotive manufacturers.
Catalysis is practiced by almost every major chemical company. Some have their own in-house catalysis divisions, but often these divisions are not permanent. Oil companies employ chemists in catalysis, but cut back on their staff in this area during the 1980s. Today, most new jobs in catalysis are in technology-driven catalyst companies that develop catalytic materials and processes. Pharmaceutical companies, too, increasingly use catalysis to make more complex drug molecules.
National laboratories working in the national interest perform catalysis research for example, the identification of catalysts to enable the production of liquid catalysts to enable the production of liquid fuel, primarily diesel fuel, from sources other than petroleum (such as coal, natural gas, or biomasses).
Chemists in this field describe themselves as patient and detail-oriented. Some say they tend to be conservative, favoring an emphasis on a specialization or single process over broad training. Nevertheless, breadth and understanding of surface chemistry and chemical engineering are considered vital to a career in catalysis. Knowledge of biology is necessary in the study of enzyme catalysis.
The field is well divided between scientists with a Ph.D., master's, and bachelor's degree. For students interested in homogeneous catalysis (where the catalyst is soluble in the reaction), a degree in organic chemistry with a strong inorganic background is useful. For those interested in heterogeneous catalysis (where the catalyst is a solid), physical chemistry, solid-state chemistry, and engineering are useful skills. Good writing and math skills are also key.
The need for more specific, controlled chemical reactions is causing the area of catalysis to grow steadily at this time. Employment in oil companies is not as promising as it was ten years ago, but greater opportunity exists in the pharmaceutical industry. In general, chemical companies do not only look for candidates with a pure organic or inorganic chemistry background; they like to see additional academic concentration or experience in a specific area such as polymers or materials science.
Catalysis is a complex science. Ask your teachers about the difference between heterogeneous and homogeneous catalysis. Journals which cover the field will give you a better understanding of the breadth of catalysis work. These include the Journal of the American Chemical Society, Journal of Organometallics, and the Journal of Organic Chemistry. The ACS Directory of Graduate Research will direct you to faculties who are engaged in catalysis research.
Experience in industry is the best way to prepare yourself for the field of catalysis. Try to get an internship during the summer.