CVD synthesis of Cu-doped cobalt spinel thin film catalysts for kinetic study of propene oxidation

Abstract

A series of Co-Cu binary oxides dispersed homogenously on an inert support were prepared by pulsed-spray evaporation chemical vapor deposition for kinetic study of catalytic combustion. The physicochemical properties of the as-prepared samples were comprehensively characterized in terms of structure, morphology and composition. The results disclosed the formation of cubic binary oxides with amorphous surface. With the progressive introduction of copper into the cobalt spinel, the crystallite size tended to increase due to the incorporation of large Cu2+ ionic radius. Co3+, Co2+, Cu2+, lattice and adsorbed oxygen species were confirmed to co-exist at the surfaces of the binary oxides. The obtained samples exhibited excellent performance for C3H6 oxidation with a high gas hourly space velocity of 150,000 mL·g−1·h−1. The light-off curves shifted towards lower temperature with more Cu incorporation, which was linked to the increase in Co3+/Co2+, and the rearrangement and synergetic effects of Co, Cu and lattice oxygen. The reaction rate increases linearly with the increase in C3H6 concentration by following r=1.12*[C3H6]0.27, without reaching kinetic limitation stage. Moreover, an attractive durability of the binary oxides was observed in the C3H6 oxidation during 50 h. This work provides an inspiration and attractive strategy to develop efficient Co-Cu binary oxides for catalytic applications.