{"title":"CaH2-promoted activity of Ni-carbonate interface for CO2 methanation","authors":"","doi":"10.1016/j.jechem.2024.09.005","DOIUrl":null,"url":null,"abstract":"<div><div>Transition metal-carbonate interfaces often act as active sites in heterogeneous catalytic reactions. The interface between transition metal and metal carbonate exhibits a dynamic equilibrium during the CO<sub>2</sub> hydrogenation reaction, involving surface carbonate hydrogenation and CO<sub>2</sub> chemisorption. Nonetheless, there have been few reports on engineering the activity of the interface between transition metal and alkaline earth metal carbonate for catalytic CO<sub>2</sub> conversion. This work demonstrated that the incorporation of CaH<sub>2</sub> in Ni/CaCO<sub>3</sub> enhances the CO<sub>2</sub> methanation activity of the catalysts. The CO<sub>2</sub> conversion for Ni/CaH<sub>2</sub>-CaCO<sub>3</sub> reached 68.5% at 400 °C, which was much higher than that of the Ni/CaCO<sub>3</sub> (31.6%) and Ni/CaH<sub>2</sub>-CaO (42.4%) catalysts. Furthermore, the Ni/CaH<sub>2</sub>-CaCO<sub>3</sub> catalysts remained stable during the stability test for 24 h at 400 °C and 8 bar. Our research revealed that CaH<sub>2</sub> played a crucial role in promoting the activity of the Ni-carbonate interface for CO<sub>2</sub> methanation. CaH<sub>2</sub> could modify the electronic structure of Ni and tune the structural properties of CaCO<sub>3</sub> to generate medium basic sites (OH groups), which are favorable for the activation of H<sub>2</sub> and CO<sub>2</sub>. In-situ Fourier transform infrared spectroscopy (FTIR) analysis combined with density functional theory calculations demonstrated that CO<sub>2</sub> activation occurs at the hydroxyl group (OH) on the CaH<sub>2</sub>-modified Ni-carbonate surface, leading to the formation of CO<sub>3</sub>H* species. Furthermore, our study has confirmed that CO<sub>2</sub> methanation over the Ni/CaH<sub>2</sub>-CaCO<sub>3</sub> catalysts proceeds via the formate pathway.</div></div>","PeriodicalId":15728,"journal":{"name":"Journal of Energy Chemistry","volume":null,"pages":null},"PeriodicalIF":13.1000,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Energy Chemistry","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2095495624006259","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Energy","Score":null,"Total":0}
引用次数: 0
Abstract
Transition metal-carbonate interfaces often act as active sites in heterogeneous catalytic reactions. The interface between transition metal and metal carbonate exhibits a dynamic equilibrium during the CO2 hydrogenation reaction, involving surface carbonate hydrogenation and CO2 chemisorption. Nonetheless, there have been few reports on engineering the activity of the interface between transition metal and alkaline earth metal carbonate for catalytic CO2 conversion. This work demonstrated that the incorporation of CaH2 in Ni/CaCO3 enhances the CO2 methanation activity of the catalysts. The CO2 conversion for Ni/CaH2-CaCO3 reached 68.5% at 400 °C, which was much higher than that of the Ni/CaCO3 (31.6%) and Ni/CaH2-CaO (42.4%) catalysts. Furthermore, the Ni/CaH2-CaCO3 catalysts remained stable during the stability test for 24 h at 400 °C and 8 bar. Our research revealed that CaH2 played a crucial role in promoting the activity of the Ni-carbonate interface for CO2 methanation. CaH2 could modify the electronic structure of Ni and tune the structural properties of CaCO3 to generate medium basic sites (OH groups), which are favorable for the activation of H2 and CO2. In-situ Fourier transform infrared spectroscopy (FTIR) analysis combined with density functional theory calculations demonstrated that CO2 activation occurs at the hydroxyl group (OH) on the CaH2-modified Ni-carbonate surface, leading to the formation of CO3H* species. Furthermore, our study has confirmed that CO2 methanation over the Ni/CaH2-CaCO3 catalysts proceeds via the formate pathway.
期刊介绍:
The Journal of Energy Chemistry, the official publication of Science Press and the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, serves as a platform for reporting creative research and innovative applications in energy chemistry. It mainly reports on creative researches and innovative applications of chemical conversions of fossil energy, carbon dioxide, electrochemical energy and hydrogen energy, as well as the conversions of biomass and solar energy related with chemical issues to promote academic exchanges in the field of energy chemistry and to accelerate the exploration, research and development of energy science and technologies.
This journal focuses on original research papers covering various topics within energy chemistry worldwide, including:
Optimized utilization of fossil energy
Hydrogen energy
Conversion and storage of electrochemical energy
Capture, storage, and chemical conversion of carbon dioxide
Materials and nanotechnologies for energy conversion and storage
Chemistry in biomass conversion
Chemistry in the utilization of solar energy