Chlorine-promoted perovskite nanocomposite as a high-performance oxygen transfer agent for chemical looping methane-assisted CO2 splitting

Abstract

Metal oxide-mediated CO2 splitting with the assistance of methane (aka chemical looping dry reforming of methane) is a novel and attractive approach for CO2 utilization. Herein, we demonstrate that doping and tailoring the redox window of strontium ferrite (SrFeO3-δ)-calcium oxide nanocomposites are effective strategies to improve the performance of chemical looping reforming. The oxygen storage capacity of this redox material is about 0.82 mol O/kg. Chlorine promotes coking in the reduction step; the tailored window not only suppresses complete oxidation of methane but also enhances CO2 transformation in a fixed-bed reactor. At 980 °C, the carbon efficiency is as high as 99%, very close to the equilibrium value. In this case, no recycling or downstream separation is needed, making the proposed scheme more efficient. In addition, both the yield of CO and the productivity of syngas remain stable over 10 redox cycles. This exceptional redox performance makes the chloride-promoted SrFeO3-δ-based nanocomposites a highly competitive and cost-effective chemical looping material.