Enhanced performance of Rh1/TiO2 catalyst without methanation in water‐gas shift reaction

Water‐gas shift (WGS) reaction is an important process for industrial hydrogen production. The side reaction of methanation often causes unavoidable loss of H 2 along with this reaction. Here, we report a Rh 1 /TiO 2 single‐atom catalyst (SAC) with appreciable loading of 0.37 wt %, which exhibited an overall CO conversion of ∼95% but without any methanation at 300°C, even under CO 2 ‐ and H 2 ‐rich WGS stream. The specific activity of this SAC was around four times higher than that of cluster catalyst, which meanwhile suffered from unfavorable methanation. It was found that Rh single atoms promoted the formation of more oxygen vacancies on the TiO 2 support to activate H 2 O to generate H 2 and prohibited the dissociation of H 2 compared with Rh clusters, leading to the enhanced activity and selectivity for WGS. © 2016 American Institute of Chemical Engineers AIChE J , 63: 2081–2088, 2017