Theoretical Insights of Ni2P (0001) Surface toward Its Potential Applicability in CO2 Conversion via Dry Reforming of Methane

This study reports the potential application of Ni 2 P as highly effective catalyst for chemical CO 2 recycling via dry reforming of methane (DRM). Our DFT calculations reveal that the Ni 2 P (0001) surface is active toward adsorption of the DRM species, with the Ni hollow site being the most energetically stable site and Ni–P and P contributing as coadsorption sites in DRM reaction steps. Free-energy analysis at 1000 K found CH–O to be the main pathway for CO formation. The competition of DRM and reverse water gas shift (RWGS) is also evidenced with the latter becoming important at relatively low reforming temperatures. Very interestingly, oxygen seems to play a key role in making this surface resistant toward coking. From microkinetic analysis, we have found greater oxygen surface coverage than that of carbon at high temperatures, which may help to oxidize carbon deposits in continuous runs. The tolerance of Ni 2 P toward carbon deposition was further corroborated by DFT and microkinetic analysis. Along with the higher probability of C oxidation, we identify poor capacity of carbon diffusion on the Ni 2 P (0001) surface with very limited availability of C nucleation sites. Overall, this study opens avenues for research in metal-phosphide catalysis and expands the application of these materials to CO 2 conversion reactions.