DOI: https://doi.org/10.29363/nanoge.interect.2021.002
Publication date: 10th November 2021
Ni single atoms supported on carbonaceous materials are an appealing solution to revalorize CO 2 due to the low cost and versatility of the support and the optimal usage of Ni and its predicted selectivity and efficiency. Herein, we have used noble carbonaceous support derived from cytosine to load Ni subnanometric sites. The large heteroatom content of the support allows the stabilization of up to 11 wt% of Ni without the formation of nanoparticles. EXAFS analysis points at Ni single atoms or subnanometric clusters coordinated by oxygen in the support. Unlike the well-known N-coordinated Ni single sites selectivity towards CO 2 reduction, O-coordinated-Ni single sites (ca. 7wt% of Ni) reduced CO 2 to CO, but subnanometric clusters (11 wt% of Ni) foster the unprecedented formation of HCOOH with 27% FE at -1.4V. Larger Ni amounts ended up on the formation of NiO nanoparticles and almost 100% selectivity towards HER.