Spinel CuFe2O4: a precursor for copper catalyst with high thermal stability and activity

Abstract

Spinel CuFe2O4 has been studied as a precursor for copper catalyst. The spinel CuFe2O4 was effectively formed on the SiO2 by calcination in air at 800 °C with the atomic ratio of Fe/Cu = 2. The spinel CuFe2O4 on the SiO2 was reduced to fine dispersion of Cu and Fe3O4 particles by the H2 reduction at 240 °C. After H2 reduction at 600 °C, sintering of Cu particles over the CuFe2O4/SiO2 (Fe/Cu = 2) was inhibited significantly, while fatal sintering of Cu particles over the Cu/SiO2 (Fe/Cu = 0) occurred. The CuFe2O4/SiO2 catalyst exhibited much higher activity and thermal stability for steam reforming of methanol (SRM), compared with the Cu/SiO2 catalyst. The spinel CuFe2O4 on the SiO2 can be regenerated after an intentional sintering treatment by calcination in air at 800 °C where the activity is also restored completely. Based on these findings, we propose that spinel CuFe2O4 is an effective precursor for a high performance copper catalyst in which the immiscible interaction between Cu and Fe (or Fe oxide) plays an important role in the stabilization of Cu particles.