Coke-resistance over Rh–Ni bimetallic catalyst for low temperature dry reforming of methane

Abstract

Methane and carbon dioxide can be converted into syngas using the prospective dry reforming of methane technology. Carbon deposition is a major cause of catalyst deactivation in this reaction, especially at low temperature. The superior stability of bimetallic catalysts has made their development more and more appealing. Herein, a series of bimetallic RhNi supported on MgAl2O4 catalysts were synthesized and used for low temperature biogas dry reforming. The results demonstrate that the bimetallic RhNi catalyst can convert CH4 and CO2 by up to 43% and 52% over at low reaction temperature (600 °C). Moreover, the reaction rate of CH4 and CO2 of RhNi–MgAl2O4 remains stable during the 20 h long time stability test, most importantly, there was no obviously carbon deposition observed over the spent catalyst. The enhanced coking resistance should be attributed to the addition of a little amount of noble metal Rh can efficiently suppress dissociation of CHX∗ species into carbon, and the high surface areas of MgAl2O4 support can also promote the adsorption and activation of carbon dioxide to generate more O∗ species. Balancing the rate of methane dissociation and carbon dioxide activation to inhibit the development of carbon deposition is a good strategy, which provides a guidance for design other high performance dry reforming of methane catalysts.