Year: 2026
Type: preprint
Abstract: CO 2 methanation is a promising route for carbon utilization, yet conventional processes remain constrained by their reliance on externally supplied H 2 and specialized catalysts. To overcome these limitations, this study introduces a self-sustained Sabatier reaction based on the submerged photosynthesis of crystallites (SPSC). In this single aqueous system, metallic Fe and Mg powders react with carbonated water to generate H 2 and CH 4 near room temperature without an added methanation catalyst. Light irradiation accelerates the production of both gases. CH 4 production scales approximately in proportion with H 2 generation across diverse reaction conditions, with both gases exhibiting similar apparent activation energies. During the reaction, plate-like FeCO 3 forms on the Fe surface, while Mg addition modifies this carbonate structure to enhance relative CH 4 formation at longer reaction times. Scavenger experiments confirm the pivotal role of electron transfer in gas production. These results demonstrate that metal oxidation, electron transfer, and surface-bound carbonate reactions drive SPSC-methanation, successfully integrating in situ H 2 generation, CH 4 formation, and metal carbonate crystallization without external H 2 input.
Source: ChemRxiv
Institution: Hokkaido University
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221985765