Preparation of a Novel Copper Catalyst in Terms of the Immiscible Interaction Between Copper and Chromium

Abstract

Based on the metallurgical point of view, we aimed to design a new form of copper catalysts with high thermal stability and activity. Delafossite CuCrO2 has been studied as a precursor for copper catalyst. The CuCrO2 was reduced to fine dispersion of Cu and Cr2O3 particles with porous structure by the treatment in H2 at 600 °C, which exhibited much higher activity and thermal stability for steam reforming of methanol (SRM) than those of the CuO and/or Cr2O3 catalysts. Sintering of Cu particles was significantly suppressed even after H2 reduction at 600 °C. Moreover, the CuCrO2 can be regenerated by calcination in air at 1,000 °C where the activity is also restored completely even after sintering at high temperatures. Fine porous structure generated by the reduction of CuCrO2 and immiscible interaction between Cu and Cr2O3 are important in stabilizing of copper nanoparticles. Based on these findings, we propose that the CuCrO2 is an effective precursor for a high performance copper catalyst.