Strong Interaction over Ru/Defects‐Rich Aluminium Oxide Boosts Photothermal CO₂ Methanation via Microchannel Flow‐Type System

Abstract

The CO2 methanation is an important component of the “power to gas” strategy, and the Ru‐Al2O3 catalyst is considered to be a state‐of‐the‐art catalyst for this reaction. Conventional Ru‐Al2O3 is prepared by wet impregnation. Due to weak interactions between Ru and the Al2O3, construction of a controllable interface between the metal and the substrate is still challenging. In this work, a UV pulse laser is used to controllably construct ultra‐small Ru nanoparticles on defects‐rich Al2O3‐x‐L in situ grown on Al foil (Ru‐Al2O3‐x‐L) for effective photothermal CO2 methanation. The catkin‐like fluff Al2O3‐x‐L efficiently traps light to ensure the light adsorption of Ru‐Al2O3‐x‐L. The defects in Al2O3‐x‐L efficiently anchors Ru. A Strong‐Metal‐Support‐Interaction (SMSI) effect is constructed between the ultra‐small Ru nanoparticles and the Al2O3‐x‐L. The Ru‐Al2O3‐x‐L exhibits remarkable photothermal catalytic performance (CH4 yield of 12.35 mol gRu−1 h−1) in the closed batch system. Then an innovative flow reactor is established based on the one‐piece Ru‐Al2O3‐x‐L microchannel catalyst. Thanks to local pressure on the edge of the microchannels, the CH4 yield is further enhanced to 14.04 mol gRu−1 h−1. Finally, an outdoor setup demonstrates the feasibility of photothermal CO2 methanation (CH4 yield of 18.00 mmol min−1). This work provides novel perspectives for the construction of multi‐level micro/nanostructures integrated catalysts for photothermal CO2 methanation.

Nanostructured Materials for Photothermal Carbon Dioxide Hydrogenation: Regulating Solar Utilization and Catalytic Performance

“…TiO 2 and Al 2 O 3 have also been used as supports for CO 2 methanation to improve the light absorption ability and photothermal catalysis . For example, the defect-rich Al 2 O 3– x -L has been constructed by a UV pulse laser to enhance the light absorption capacity and efficiently anchor Ru . A nanoantenna catalyst composed of an Al 2 O 3 nanopowder substrate and Rh nanoclusters has been prepared.…”

“…89 For example, the defect-rich Al 2 O 3−x -L has been constructed by a UV pulse laser to enhance the light absorption capacity and efficiently anchor Ru. 12 A nanoantenna catalyst composed of an Al 2 O 3 nanopowder substrate and Rh nanoclusters has been prepared. The nanostructure has an enhanced light absorption ability in UV and NIR region (Figure 4f), exhibiting a methanation rate of 550 mmol g −1 h −1 and almost 100% selectivity under concentrated light irradiation.…”

“…Photothermal catalysis, which combines photo- and thermochemical contributions of sunlight, − has become a rapidly developing and exciting research field. ,,, In particular, photothermal CO 2 hydrogenation (CO 2 + H 2 → chemicals) provides a promising way to convert CO 2 and store green H 2 produced by renewable energy, ,− which has several advantages in comparison with other catalytic modes. Compared with thermocatalysis, the photothermal catalysis can not only mitigate the fossil energy consumption but also alter the electronic structure of the catalysts under sunlight irradiation to regulate the CO 2 reduction selectivity. ,, Although photocatalysis can convert CO 2 in the absence of H 2 (CO 2 + H 2 O → chemicals), the photothermal CO 2 hydrogenation has exclusive advantages.…”

Ultrafast materials synthesis and manufacturing techniques for emerging energy and environmental applications

“…A particular advantage of laser-assisted techniques is their high spatial and temporal resolution, allowing precise and controllable fabrication of nanomaterials and nanostructures in desired applications. [67][68][69][70][71][72] (3) Microwave: microwave-assisted methods (Fig. 2c) utilize high-frequency electromagnetic radiation (e.g., microwave) as an energy source and convert it into heat rapidly, which turns precursors into desired products.…”

“…A particular advantage of laser-assisted techniques is their high spatial and temporal resolution, allowing precise and controllable fabrication of nanomaterials and nanostructures in desired applications. 67–72…”