Effects of trace amount of noble metal (Pd/Rh) on the performance of Co-clay catalysts for heavy oil upgrading

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

This communication reports the promotional effects of small amounts of Pd and Rh on the hydrodesulfurization (HDS) and hydrocracking (HC) activities of high porous saponite (HPS) supported Co catalysts. During catalyst preparation, HPS was first modified with the noble metal(s) using an incipient wetness impregnation technique followed by cobalt loading through an ion exchange method. Temperature-programmed reduction (TPR) studies showed that the reducibility of the catalysts was significantly improved by the noble metals (Pd, Rh). Higher metal dispersion and hydrogen spillover effects were considered to be the main reasons for the increased reducibility. Both the HC and HDS activities of noble metal-promoted Co/HPS catalysts were found to be higher than that of plain Co/HPS catalysts, when evaluated in a batch autoclave reactor using vacuum gas oil as feedstock. Furthermore, Rh displayed higher promotional effects as compared to Pd in both HC and HDS. This higher activity is consistent with the TPR results, which showed superior reducibility of the Rh promoted catalysts. A particular interesting finding of this study pertained to a synergic effects of bi-noble (Pd-Rh) metal promoted Co/HPS catalyst. It was observed that a trace amount of Rh and Pd exhibited a significant enhancement of the catalytic activity of Co/HPS. The activity of the bimetallic catalyst was comparable to that of the Rh promoted catalyst with higher Rh loading. It should be noted that this synergic effects was achieved with a lower overall noble metal content, which is crucial for the economic feasibility of the catalyst for industrial application. The coke deposition on the Pd-Rh promoted catalyst was also found be the lower than that of the plain and single noble metal promoted Co/HPS, which is a positive aspect for a longer catalyst lifetime. Therefore, this study revealed that trace amount of noble metal promoted Co/HPS catalyst holds great promise for HC and HDS of heavy oil.

Original languageEnglish
Title of host publication2006 AIChE Spring National Meeting
StatePublished - 2006
Externally publishedYes

Publication series

NameAIChE Annual Meeting, Conference Proceedings

Keywords

  • Bimetallic catalysts
  • Clay
  • Co
  • HC
  • HDS
  • Heavy oil upgrading
  • Noble metals
  • TPR

ASJC Scopus subject areas

  • General Chemical Engineering
  • General Chemistry

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