Designing catalysts to catalyze reactions along the intended reaction path, for example, carbon dioxide (CO2) methanation, has received a lot of attention, but remains a huge challenge. Based on this,Researcher Su Fabing and Researcher Xu Wenqing of the Institute of Process Engineering, Chinese Academy of Sciences, and Researcher Li Lina of the Shanghai Advanced Research Institute of the Chinese Academy of SciencesA Ru1Ni single-atom alloy (SAA) catalyst (Ru1Ni SiO2) was reported, which was prepared by an electrical substitution reaction between RuCl3 and Ni nanoparticles (Ni NPS). Selectivity and catalytic activity of RU1Ni SiO2 catalyst for CO2 hydrogenation to CH4 (TOF value 4000 10-3 S-1) was significantly higher than that of Ni SiO2 catalyst (TOF value was 4.).40 10-3 S-1) and most of the reported NI-based catalysts (with a TOF value of 1.).03 10-3 to 1100×10-3 s-1）。
VASP Interpretation
With DFT calculations, the authors investigated the possible reaction pathways and calculated energy distribution maps for the hydrogenation of CO2 on Ni and Ru1Ni SAA. First, CO2 and H2 molecules are absorbed in parallel at the Ni site (IS). Subsequently, HCO* intermediates are generated at the Ni site (IS IM1 via TS1;The energy base is 093 ev）。The energy barrier to be overcome to decompose CO2 into Co* and O* is 127 EV (IS IM2 via TS2), indicating that CO2 is more easily converted to HCOo* at the Ni site than dissociated to CO*. HCO* intermediates are then overcome106 EV (IM1 IM3 via TS3) is decomposed into CHO*.
For Ru1Ni SAA, the two O atoms in CO2 are first bound to the Ru-Ni interface site, and H2 is adsorbed at the Ni site (IS). CO2 then proceeds to hydrogenate HCOo*, which needs to be overcome117 EV (IS IM1 via TS1). Decomposition to co* only needs to overcome 0An energy barrier of 93 EV (IS IM2 via TS2) suggests that the reaction may follow the CO* pathway.
For Ni, the Co* molecule is adsorbed on the Ni surface and reacts with H* to form Cho* (is im1 via TS1;The energy base is 164 ev）。The resulting CHO* is further reacted with H* by TS2 to generate CH2O* (IM1 IM2;The energy base is 240 eV) can be converted to methane by CH3O* as an intermediate (IM4FS via TS4;The energy base is 264 ev）。The results showed that the *CO path was more energetically favorable than the HCO* path on the NI catalyst.
single-atom ru alloyed with ni nanoparticles boosts co2 methanation. small,, doi: ht-tps: