Improving steam-reforming performance by nanopowdering CuCrO2

In this study, the delafossite type CuCrO2 nanopowder was used as a precursor for preparing Cu-based catalyst for steam reforming of methanol (SRM). The efficiency of hydrogen generation was greatly improved by reducing the size of CuCrO2 to nanoscale. The reduction temperature of Cu metal particles from CuCrO2 decreased from 600 °C to 200 °C due to this size effect. Additionally, because of lowered activation energy, CuCrO2 nanopowder could be reduced by methanol vapor. Thus the CuCrO2 nanopowder, prepared by GNP method, had much higher SRM efficiency than bulk CuCrO2 and the commercial SRM catalyst, even without H2 activation process. The SEM images revealed that the powder retained a cotton candy-like porous structure after reduction treatment. The TEM images showed that the Cu particles were about 5 nm in diameter and well dispersed on Cr2O3 after the reduction of CuCrO2 nanopowder at 500 °C. The catalyst was evaluated by the generation rate with steam reforming of methanol, and the peak hydrogen generation rate read as high as 2550 ml/min g-cat at 360 °C with hydrogen activation. CuCrO2 nanopowder showed high catalytic activity even without reduction treatment, and hydrogen generation rate read as high as 1740 ml/min g-cat at 360 °C.