Low-temperature carbon dioxide conversion via reverse water-gas shift thermochemical looping with supported iron oxide

Abstract

Carbon dioxide utilization via the reverse water-gas shift (RWGS) reaction is a potentially scalable method to mitigate rising global carbon dioxide emissions if high carbon monoxide yields and reaction rates can be achieved at low reaction temperatures. Iron oxide (Fe 2 O 3 ) has been extensively studied as a chemical looping material in RWGS, but nearly all studies were performed at high temperatures, where sintering and deactivation occur. Here, we investigate Fe 2 O 3 as an RWGS chemical looping metal oxide at low reaction temperatures (500°C for both oxidation and reduction steps) and find that a direct, reversible, and stable metal/oxide phase transition results in a high carbon monoxide yield of 386 mL CO/g-Fe 2 O 3 /cycle. The measured carbon monoxide yield remains relatively stable for 350 redox cycles or 12.1 days on stream. The affordability and abundance of Fe 2 O 3 , the high carbon monoxide yield, and its extended time-on-stream without substantial performance degredation makes Fe 2 O 3 a RWGS chemical looping metal oxide with a promising chance of commercialization.