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

• Rh/Co showed superior activity and H2 yield for ATR of diesel.
• Rh/La showed low selectivity towards by-product formation.
• Rh/Co and Rh/La showed low diesel slip for ATR.
• Smart bimetallic combinations, with low Rh content, result in high activity.

The objective of this paper was to study the influence three promoters (Co, La, Mn) had on the catalytic activity of Rh-based catalysts for autothermal reforming of diesel. The catalysts were supported on CeO2-ZrO2 and the loading was 1 wt.% Rh and 6 wt.% promoter. The catalytic activity was evaluated in a monolith bench scale reactor with Swedish Environmental diesel, MK1. The process parameters employed at the ATR experiments were; O2/C ∼ 0.45, H2O/C ∼ 2.5 and GHSV ∼ 50,000 h−1, meanwhile the reactor temperature was ramped from 700 °C to 950 °C. The catalysts were compared based on their fuel conversion, H2 yield and the selectivity of different short-chain hydrocarbons.The results showed that all three catalysts had both high fuel conversion and H2 yield in the optimal ATR operation temperatures. The H2 yield and fuel conversion were increasing in the order Rh/Mn, Rh/La, Rh/Co. To get further insight in the difference between the materials the fresh and aged catalytic materials were characterized. The characterization methods used were H2-temperature programmed reduction (H2-TPR), powder X-ray diffraction (XRD), and BET surface measurements. The BET surface measurements showed that promotion with La gave improved thermal stability of the material. The XRD showed a high dispersion of all metals except Co, which was present as crystals in the size range of the particles of the support.

Figure optionsDownload as PowerPoint slide