Heterogeneous catalysis is a phenomenon in which a solid material speeds up a chemical reaction without being part of the reaction's overall stoichiometric equation. Sequences of reactions involving fluid-phase reagents and the exposed layer of the solid catalyst surface are commonly used in heterogeneous catalysis. Because of its ability to accelerate a chemical reaction to equilibrium and to selectively accelerate a desirable chemical reaction of complex chemical processes to equilibrium, heterogeneous catalysis by solids plays a vital role in the chemical industry and environmental remediation. Heterogeneous catalysis is a pillar of the chemical and energy sectors, and it will be a key science in accelerating the transition to carbon-neutral operations.