Sorption-enhanced steam reforming of glycerol over Ni[sbnd]Cu[sbnd]Ca[sbnd]Al catalysts for producing fuel-cell grade hydrogen

Abstract

The concentration of CO in the high-purity hydrogen from sorption-enhanced steam reforming (SESR) processes is usually too high to be directly used in fuel cells. Herein, we report a production of fuel-cell grade H2 with <30 ppm CO through SESR of glycerol (SESRG), a by-product of biodiesel manufacture. High purity H2 can be produced by employing a catalyst-sorbent hybrid material composed of Ni as catalyst, CaO as CO2 sorbent and Ca12Al14O33 as spacer. By introducing copper as promoter, the performance of the bi-functional catalyst could be modified to produce a 97.15 vol% purity of H2 with 28 ppm CO. With an optimized Ni/Cu ratio, the 7.5Ni–7.5Cu catalyst shows the excellent stability for producing about 97% H2 with <30 ppm CO for ten cycles. The characterizations and model reaction tests indicate that copper can affect CO, CO2 hydrogenation and water gas shift reaction to adjust the performance of SESRG reaction. The results presented here show the promise of tuning the catalyst composition for achieving high quality H2 through SESR processes.