In situ control of the composition and performance of a bimetallic alloy catalyst: The selective hydrogenation of acetylene over Pt/Pb

WILLIAMS, F J; PALERMO, A; LAMBERT, R M

JOURNAL OF PHYSICAL CHEMISTRY B - (Print)

AMER CHEMICAL SOC

Año: 2002 vol. 106 p. 10215 - 10219

1520-6106

The application of a Pb2+ conducting solid electrolyte (Pb-􏱆′′ alumina) to electrochemical control of catalyst performance is reported. XPS data show that pumping of Pb to/from a thin film platinum catalyst from/to the solid electrolyte provides a controlled, reversible, and reproducible way of altering the surface composition of the resulting Pt/Pb surface alloy under conditions of acetylene hydrogenation. With increasing Pb concentration a large increase in partial hydrogenation selectivity occurs from 20% (pure Pt surface) to 85% (∼26% Pb surface alloy). The results demonstrate that the surface composition and catalytic performance of bimetallic alloy catalysts can be dramatically and reversibly altered under working conditions by electrochemical means.