Rh-based catalysts for dry reforming of methane: Effect of promoter on aluminum oxide support

Rh-based catalysts supported on aluminum oxides promoted with La or P were investigated for dry reforming of CH4 with CO2. Due to a bifunctional mechanism of reaction which involves the activation of CH4 on noble metal sites and of CO2 on the support, the catalytic activity decreases with increasing surface acidic character of the support. Consequently catalysts containing phosphorous on the support are less active despite their higher Rh dispersion. Moreover, the introduction of phosphorous in the structure (AlPO4) strongly reduces the thermal stability of the catalysts under reaction conditions.