Hydroxylated TiO-induced high-density Ni clusters for breaking the activity-selectivity trade-off of CO hydrogenation.

The reverse water gas shift reaction can be considered as a promising route to mitigate global warming by converting CO into syngas in a large scale, while it is still challenging for non-Cu-based catalysts to break the trade-off between activity and selectivity. Here, the relatively high loading of Ni species is highly dispersed on hydroxylated TiO through the strong Ni and -OH interactions, thereby inducing the formation of rich and stable Ni clusters (~1 nm) on anatase TiO during the reverse water gas shift reaction. This Ni cluster/TiO catalyst shows a simultaneous high CO conversion and high CO selectivity. Comprehensive characterizations and theoretical calculations demonstrate Ni cluster/TiO interfacial sites with strong CO activation capacity and weak CO adsorption are responsible for its unique catalytic performances. This work disentangles the activity-selectivity trade-off of the reverse water gas shift reaction, and emphasizes the importance of metal-OH interactions on surface.