The importance of being together

Abstract

Platinum catalyzes several chemical and electrochemical reactions that are central to humankind's use of energy, such as the electrochemical reduction of molecular oxygen, carbon monoxide oxidation, and the water-gas shift reaction to produce carbon dioxide and hydrogen from carbon monoxide and water. Two reports in the current issue provide insights into which platinum coordination number—defined as the number of nearest neighbors—may provide the highest catalytic activities for these reactions. On page 185, Calle-Vallejo et al. use the concept of generalized coordination numbers to show that concave atomic sites on a platinum single crystal are highly active for oxygen electroreduction (1). On page 189, Ding et al. use spectroscopic techniques to determine what role isolated Pt atoms play in CO oxidation and the water-gas shift reaction (2).