Several Ce–La and Ce–Zr oxides, with different transition metal additives, were studied for the dry reforming of methane. A rapid screening technique was developed to measure reforming and coking rates at low partial pressures. It is a good indicator of catalyst behavior at higher conversions and partial pressures. Following rapid screening, select catalysts were examined at longer times on stream. Those containing Ni and Co together were the most stable. Catalysts containing Ce–La oxides lacked practicality, partly due to more reverse water-gas shift. Catalysts containing Ce–Zr oxides fared better, with Ce/Zr = 3 (molar) showing the best stability for Ni-based catalysts. Reaction and deactivation results for Ni- and Ni/Co-containing catalysts could be explained partly in terms of DFT calculations for model surfaces, and partly in terms of spent catalyst characterizations. The Ni interacts strongly with the mixed oxides, even when it is in a mostly reduced state, as in Ce–Zr.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry