Ni/CeO2 catalysts with high CO2 methanation activity and high CH4 selectivity at low temperatures

CO2 methanation is a well-known reaction that is of interest as a capture and storage (CCS) process and as a renewable energy storage system based on a power-to-gas conversion process by substitute or synthetic natural gas (SNG) production. Integrating water electrolysis and CO2 methanation is a highly effective way to store energy produced by renewables sources. The conversion of electricity into methane takes place via two steps: hydrogen is produced by electrolysis and converted to methane by CO2 methanation. The effectiveness and efficiency of power-to-gas plants strongly depend on the CO2 methanation process. For this reason, research on CO2 methanation has intensified over the last 10 years. The rise of active, selective, and stable catalysts is the core of the CO2 methanation process. Novel, heterogeneous catalysts have been tested and tuned such that the CO2 methanation process increases their productivity. The present work aims to give a critical overview of CO2 methanation catalyst production and research carried out in the last 50 years. The fundamentals of reaction mechanism, catalyst deactivation, and catalyst promoters, as well as a discussion of current and future developments in CO2 methanation, are also included.

Supported Catalysts for CO2 Methanation: A Review

Recent progress in selective CO removal in a H2-rich stream

Mesostructured silica nanoparticles (MSN) and Ni loaded onto MSN (Ni/MSN) for the methanation of CO2 were prepared by the sol–gel and impregnation methods. Catalytic testing was conducted in the temperature range of 423–723 K under atmospheric pressure in the presence of H2. Ni supported on MSN was compared with others types of support such as MCM-41 (Mobile Crystalline Material), HY (protonated Y zeolite), SiO2 and γ-Al2O3. The activity of CO2 methanation followed the order: Ni/MSN > Ni/MCM-41 > Ni/HY > Ni/SiO2 > Ni/γ-Al2O3. The nitrogen physisorption and pyrrole adsorbed IR spectroscopy results indicated that the high activity of Ni/MSN is due to the presence of both intra- and inter-particle porosity which led to the high concentration of basic sites. In addition, the correlation between N–H band intensity and the turnover frequency revealed that the methanation activity increased with increasing of the concentration of basic sites. The presence of defect sites or oxygen vacancies in MSN was responsible for the formation of surface carbon species, while Ni sites dissociated hydrogen to form atomic hydrogen. The surface carbon species then interacted with atomic hydrogen to form methane. The Ni/MSN catalyst performed with good stability and no deactivation up to 200 h.

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Highly active Ni-promoted mesostructured silica nanoparticles for CO2 methanation

Toward computational screening in heterogeneous catalysis: Pareto-optimal methanation catalysts

Complete removal of carbon monoxide in hydrogen-rich gas stream through methanation over supported metal catalysts

Hydrogen without CO or CO 2 was produced through the reaction of carbons with water and NaOH. Carbon black reacted with NaOH in the presence of water vapor at temperatures > 700 K to form CO x -free hydrogen and Na 2 CO 3 , whereas carbon black was gasified with water vapor in the absence of NaOH at temperatures > 900 K to form CO and hydrogen. Therefore, hydrogen was produced according to the following equation: C + 2NaOH + H 2 O → Na 2 CO 3 + 2H 2 . Alkali hydroxides (LiOH, KOH, and RbOH) other than NaOH also promoted the formation of CO x -free hydrogen at temperatures > 700 K through the reaction of carbon black and water vapor. Hydrogen formation through the reaction of carbon black, alkali hydroxides, and water vapor was enhanced by the addition of Al 2 O 3 , TiO 2 , MnO 2 , V 2 O 5 , CeO 2 , Rh metal, and Ru metal.

Toru Shimizu

Papers

Complete removal of carbon monoxide in hydrogen-rich gas stream through methanation over supported metal catalysts

Formation of Hydrogen without COx from Carbon, Water, and Alkali Hydroxide