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

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.