Kinetic studies of CH4 oxidation over Pt–NiO/δ-Al2O3 in a fluidised bed reactor Original Research Article

The oxidation of CH4 over Pt–NiO/δ-Al2O3 has been studied in a fluidised bed reactor as part of a major project on an autothermal (combined oxidation–steam reforming) system for CH4 conversion. The kinetic data were collected between 773 and 893 K and 101 kPa total pressure using CH4 and O2 compositions of 10–35% and 8–30%, respectively. Rate–temperature data were also obtained over alumina-supported monometallic catalysts, Pt and NiO. The bimetallic Pt–NiO system has a lower activation energy (80.8 kJ mol−1) than either Pt (86.45 kJ mol−1) and NiO (103.73 kJ mol−1). The superior performance of the bimetallic catalyst was attributed to chemical synergy. The reaction rate over the Pt–NiO catalyst increased monotonically with CH4 partial pressure but was inhibited by O2. At low partial pressures (<30 kPa), H2O has a detrimental effect on CH4 conversion, whilst above 30 kPa, the rate increased dramatically with water content.