Coupling Enteromorpha prolifera-derived N-doped biochar with Cu-Mo2C clusters for selective CO2 hydrogenation to CO

CO 2 conversion to CO via the reverse water-gas shift (RWGS) reaction is limited by a low CO 2 conversion rate and CO selectivity. Herein, an efficient RWGS catalyst is constructed through Enteromorpha prolifera –derived N-rich mesoporous biochar (EPBC) supported atomic-level Cu-Mo 2 C clusters (Cu-Mo 2 C/EPBC). Unlike traditional activated carbon (AC) supported Cu-Mo 2 C particles (Cu-Mo 2 C/AC), the Cu-Mo 2 C/EPBC not only presents the better graphitization degree and larger specific surface area, but also uniformly and firmly anchors atomic-level Cu-Mo 2 C clusters due to the existence of pyridine nitrogen. Furthermore, the pyridine N of Cu-Mo 2 C/EPBC strengthens an unblocked electron transfer between Mo 2 C and Cu clusters, as verified by X-ray absorption spectroscopy. As a result, the synergistic effect between pyridinic N anchoring and the clusters interaction in Cu-Mo 2 C/EPBC facilitates an improved CO selectivity of 99.95% at 500 ​°C compared with traditional Cu-Mo 2 C/AC (99.60%), as well as about 3-fold CO 2 conversion rate. Density functional theory calculations confirm that pyridine N-modified carbon activates the local electronic redistribution at Cu-Mo 2 C clusters, which contributes to the decreased energy barrier of the transition state of CO∗+O∗+2H∗, thereby triggering the transformation of rate-limited step during the redox pathway. This biomass-derived strategy opens perspective on producing sustainable fuels and building blocks through the RWGS reaction. N-doped biochar supported Cu-Mo 2 C cluster (Cu-Mo 2 C/EPBC) was constructed via an Enteromorpha prolifera -derived strategy. Unlike traditional Cu-Mo 2 C/AC (activated carbon), Cu-Mo 2 C/EPBC presents the better graphitization degree and larger specific surface area, while can firmly anchors Cu-Mo 2 C clusters due to riched pyridine-N. Cu-Mo 2 C/EPBC shows an improved CO selectivity of 99.95 ​% at 500 ​°C compared with Cu-Mo 2 C/AC (99.60 ​%), and about 3-fold CO 2 conversation rate. • Enteromorpha prolifera -derived mesoporous biochar supported Cu-Mo 2 C catalyst was prepared. • The existence of pyridine N in EPBC facilitates the formation of atomic-level Cu-Mo 2 C clusters. • Cu-Mo 2 C/EPBC exhibits the high conversation rate for selective CO 2 hydrogenation to CO.