Evaluation of Co, La, and Mn promoted Rh catalysts for autothermal reforming of commercial diesel: Aging and characterization

Abstract

In this study, three bimetallic catalysts are evaluated for autothermal reforming (ATR) of fuels (1wt.% Rh and 6wt.% X (X=Co, La or Mn) supported on high-surface area CeO2–ZrO2). The catalysts are aged for approximately 35h and carefully characterized both as fresh and aged materials. The objective is to illuminate the changes in material properties after time on stream as well as the differences among the materials. The changes in material properties are evaluated by H2-TPR, BET surface area analysis, TEM, SEM, and STEM. The material’s tendency to coke is investigated by TPO analysis.The three materials exhibit promising initial activity. However, the Co-promoted sample decreases sharply in activity after 25h of operation. Meanwhile, the other two materials display a more stable activity throughout the evaluated time. The deactivation of the Co-promoted material could be linked to the high amount of coke deposited during operation. Based on the results from the activity evaluation and characterization, the material promoted with lanthanum displays the most promising results. The addition of lanthanum resulted in a catalyst that was both stable and had high activity, even though a low rhodium loading is used. The material also shows superior thermal resistance compared to the other two materials. In addition, the tendency to coke is significantly lower compered to the other materials, which is especially beneficial when dealing with ATR of complex fuels.