Multifunctional Pd/Ni-Co catalyst for hydrogen production by chemical looping coupled with steam reforming of acetic acid

Abstract

High yield of high‐purity H2 from acetic acid, a model compound of bio‐oil obtained from the fast pyrolysis of biomass, was produced by sorption‐enhanced steam reforming (SESR). An oxygen carrier was introduced into a chemical loop (CL) coupled to the cyclical SESR process to supply heat in situ for the endothermic sorbent regeneration to increase the energy efficiency of the process. A new multifunctional 1 %Pd/20 %Ni–20 %Co catalyst was developed for use both as oxygen carrier in the CL and as reforming catalyst in the SESR whereas a CaO‐based material was used as CO2 sorbent. In the sorbent–air regeneration step, the Ni–Co atoms in the catalyst undergo strong exothermic oxidation reactions that provide heat for the CaO decarbonation. The addition of Pd to the Ni–Co catalyst makes the catalyst active throughout the whole SESR–CL cycle. Pd significantly promotes the reduction of Ni–Co oxides to metallic Ni–Co during the reforming stage, which avoids the need for a reduction step after regeneration. H2 yield above 90 % and H2 purity above 99.2 vol % were obtained.