Catalytic combustion of methane : copper oxide supported on high-specific-area spinels synthesized by a sol–gel process

Abstract

Three spinels (MgAl₂O₄, ZnAl₂O₄ and CaAl₂O₄) have been synthesized using a sol–gel process coupled with supercritical drying. After calcination at 1000 K, specific areas as high as 300 m² g^–1 can be preserved. Deposition of copper oxide on such carriers leads to the formation of catalysts active in methane combustion. The catalytic activity is strictly proportional, at low conversion levels, to the number of Cu²⁺ ions deduced from FTIR measurements of carbon monoxide adsorption. By comparison with spinels prepared by impregnation of alumina with nitrate salts, the use of a sol–gel process allows an increase in the dispersion state of the active phase.