Surface modification of dual-phase ceramic membrane reactor for coupling catalytic CO2 conversion with partial oxidation of methane

Abstract

The oxygen transport membrane (OTM) reactor is a particularly promising process for CO2 conversion and utilization through coupling the thermochemical decomposition of CO2 with the partial oxidation of methane (POM). However, its low CO2 decomposition efficiency and poor operational stability in corrosive atmospheres are the main challenges for practical application. In this work, the porous layers of LaMO3-δ (M = Fe, Co, Ni) and Ce0.8Zr0.2O2-δ (CZ), with different functions separately, were coated on both sides of the Ce0.9Pr0.1O2-δ-Pr0.6Sr0.4Fe0.9Al0.1O3-δ (CP-PSFA) dual-phase membrane. The presence of oxygen vacancy and transition ions M with the valence of +2/+3 in the LaMO3-δ is conducive to catalyzing CO2 conversion. The LaCoO3-δ porous layer exhibits the best oxygen permeability and CO2 conversion, and the performance of POM is greatly enhanced by the in situ Ni-doped CZ porous layer. After a long-term test at 925 °C, the oxygen permeation flux of the LaCoO3-δ/CP-PSFA/CZ-Ni maintains at 0.96 mL cm−2 min−1, the conversion rate of CH4 and CO2 maintains at 23 % and 45 % respectively, and the syngas yield reaches 6.3 mL cm−2 min−1. The sandwich-like OTM reactor with functional porous layers has broad research prospects in the CO2 conversion and utilization field.