Synthesis of Co-Cu/La2O3 Pervoskites for Hydrogenation of CO

Abstract

Two families of LaCo_1-xCu_xO_3-d perovskites were synthesized by the conventional citrated complex and milling method. An introduction of copper in perovskite lattice gives rise to a slightly distorted structure of LaCoO₃ and influences the perovskite reducibility. Temperature programmed reduction analysis indicates the reduction of Co³⁺, Cu²⁺ respectively to Co²⁺ and metallic copper over conventional samples at 310-580 ºC while that on ground perovskites in the temperature range of 320-610 ºC. The reduction of La(Co,Cu)O₃ yields a finely dispersed bimetal on a La₂O₃ support. The proximity of Co³⁺ and Cu²⁺ in perovskite structure leads to the formation of cobalt-copper alloy after reduction, which acts as active sites for the hydrogenation of CO into alcohols and hydrocarbon products.