Kinetics decoupling activity and selectivity of Pt nanocatalyst for enhanced glycerol oxidation performance

Abstract

Abstract Herein, we demonstrate a kinetics and a mechanistic strategy to disentangle the origins of the significantly improved activity and selectivity of Pt‐catalyzed glycerol oxidation. The unchanged reactant reaction orders and activation energies suggest the same kinetics despite variable Pt particle sizes, based on which a Michaelis–Menten kinetics treatment is conducted to individually quantify the number and activity of Pt active site. Together with multiple characterization results, the volcano‐shaped activity is mainly arising from the quantity change of Pt active site. Moreover, the atomic structure of bimetallic Pt─Sb catalyst is well elucidated by the formation of Pt─SbO interface along with partial Sb incorporation into Pt lattice, chelating with glycerol to poison Pt active sites for primary hydroxyl activation while creating interfacial site for second hydroxyl activation, further evidenced by kinetics shift. The kinetics strategy could be extended to other metal catalysts with simultaneously high activity and selectivity.