Designing single-metal-atom catalysts that efficiently drive green chemical reactions is simply a matter of looking up readily available data and using that information to choose the metal and its support material, according to a theoretical study (Nat. Catal. 2018, DOI: 10.1038/s41929-018-0063-z). Low-cost, energy-efficient strategies for producing hydrogen—for example, via catalytic water splitting—and for using hydrogen as a non-carbon-emitting fuel—for example, in fuel cells—rank among today’s most important energy research problems. Traditionally, researchers used a trial-and-error approach to design the catalytic electrodes that drive those processes. Now, Xiao Cheng Zeng of the University of Nebraska, Lincoln, and coworkers have developed a set of simple, theory-based design principles. The predictive model ties the electrocatalytic activity of single metal atoms supported on graphene—a promising family of inexpensive catalysts—to readily available data, such as the metal’s coordination number and the electronegativities of the metal and its nearest neighbors. The goal is to have a way for researchers to plug in these values and obtain a back-of-the-envelope calculation for catalytic activity, Zeng says. The team built the model by evaluating nearly 30 transition metals in 112 configurations and showed it agrees with available experimental results.