Heterogeneous Catalysis and a Sustainable Future

The processes that convert fossil resources into fuels and chemicals are essential to modern life. One central sustainable energy source, which we need to harvest much more efficiently and at a much larger scale than we do today, is sunlight. Traditionally, the field of catalysis is divided into three areas: heterogeneous, homogeneous, and enzyme catalysis. Heterogeneous catalysts are present in a phase different from that of the reactants; typically, the reactants are in the gas or liquid phase, whereas the catalyst is a solid material. Homogeneous catalysts operate in the same phase as the reactants, and enzyme catalysts are specialized proteins. The chemically active part of enzymes is often a tiny part of the protein, and enzyme catalysis can be viewed as a special kind of heterogeneous catalysis.