Chromium free high temperature water–gas shift catalyst for the production of hydrogen from waste derived synthesis gas

Abstract

A comparative study between monometallic (Me−CeO2, Me=Zn, Cu, Fe and Co) and Ni-doped bimetallic (Me−Ni−CeO2) catalysts has been performed in the high temperature water-gas shift (HT−WGS) reaction using waste derived synthesis gas. Experimental results revealed that Me−Ni−CeO2 exhibited higher catalytic performance than simple Me−CeO2 catalysts. Within the Me−Ni−CeO2 series, Co−Ni−CeO2 exhibited excellent and stable catalytic performance (CO conversion>90%) at a very high GHSV of 143,000h−1. The existence of high concentration of Ce3+ ions and oxygen vacancies on the catalyst surface were responsible for the increased WGS activity of Co−Ni−CeO2. In addition, Co−Ni−CeO2 maintains a stable performance for 50h. However, commercial Fe2O3-Cr2O3 catalyst showed a steep decline from their initial CO conversion values 15–10% within 5h.