Reforming of a model biogas on Ni and Rh–Ni catalysts: Effect of adding La

Ni catalysts supported on γ–Al2O3 modified by Rh and La were prepared and evaluated on the reforming of a model biogas. The catalysts were characterized by EDS, XRD, TPR, XANES and surface area estimation (BET). The results showed that in the original Ni catalyst, the Ni interacted strongly with the alumina support, exhibiting high reduction temperatures in TPR tests. In the catalytic tests, the addition of Rh on Ni catalysts improved CH4 conversion but also increased carbon deposition, possible by causing the segregation of Ni species under the reaction conditions. The presence of La on Ni catalysts reduced the carbon deposition by favoring the gasification of carbon species. Addition of synthetic air to the process improved the CH4 conversion and also decreased the carbon formation. The catalysts Ni, Rh–NiLa, and Rh showed good results in the conversion of model sulfur-free biogas, which suggests that they are promising catalysts to be tested in conversion of real biogas.

► Ni catalysts supported on γ-Al2O3 were prepared with and without Rh and La.
► Catalysts were tested in the reforming of a model biogas with oxygen addition.
► Rh increased the amount of reducible Ni species.
► Rh improved the CH4 conversion and also increased the carbon deposition.
► La reduced the carbon deposition by a favoring of gasification of carbon species.