Guo Chan, Tang Yunxiang, Yang Zhengyi, Zhao Tingting, Liu Jiurong, Zhao Yufei, Wang Fenglong
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of Education, Shandong University, Jinan 250061, P. R. China.
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
ACS Nano. 2023 Dec 12;17(23):23761-23771. doi: 10.1021/acsnano.3c07630. Epub 2023 Nov 20.
Carbon dioxide (CO) hydrogenation to methane (CH) is regarded as a promising approach for CO utilization, whereas achieving desirable conversion efficiency under mild conditions remains a significant challenge. Herein, we have identified ultrasmall Ru nanoparticles (∼2.5 nm) anchored on MnCoO nanosheets as prospective photothermal catalysts for CO methanation at ambient pressure with light irradiation. Our findings revealed that MnCoO nanosheets exhibit dual functionality as photothermal substrates for localized temperature enhancement and photocatalysts for electron donation. As such, the optimized Ru/MnCoO-2 gave a high CH production rate of 66.3 mmol g h (corresponding to 5.1 mol g h) with 96% CH selectivity at 230 °C under ambient pressure and light irradiation (420-780 nm, 1.25 W cm), outperforming most reported plasmonic metal-based catalysts. The mechanisms behind the intriguing photothermal catalytic performance improvement were substantiated through a comprehensive investigation involving experimental characterizations, numerical simulations and density functional theory (DFT) calculations, which unveiled the synergistic effects of enhanced charge separation efficiency, improved reaction kinetics, facilitated reactant adsorption/activation and accelerated intermediate conversion under light irradiation over Ru/MnCoO. A comparison study showed that, with identical external input energy during the reaction, Ru/MnCoO-2 had a much higher catalytic efficiency compared to Ru/TiO and Ru/AlO. This study underscores the pivotal role played by photothermal supports and is believed to engender a heightened interest in plasmonic metal nanoparticles anchored on photothermal substrates for CO methanation under mild conditions.
将二氧化碳（CO₂）加氢转化为甲烷（CH₄）被认为是一种很有前景的CO₂利用方法，然而在温和条件下实现理想的转化效率仍然是一项重大挑战。在此，我们确定了锚定在MnCo₂O₄纳米片上的超小Ru纳米颗粒（约2.5 nm）作为在常压下光照条件下用于CO₂甲烷化的潜在光热催化剂。我们的研究结果表明，MnCo₂O₄纳米片具有双重功能，既是用于局部温度升高的光热底物，又是用于电子供体的光催化剂。因此，优化后的Ru/MnCo₂O₄-2在230℃、常压和光照（420 - 780 nm，1.25 W/cm²）条件下，CH₄产率高达66.3 mmol g⁻¹ h⁻¹（相当于5.1 mol g⁻¹ h⁻¹），CH₄选择性为96%，优于大多数已报道的基于等离子体金属的催化剂。通过包括实验表征、数值模拟和密度泛函理论（DFT）计算在内的综合研究，证实了这种引人注目的光热催化性能提升背后的机制，揭示了光照下Ru/MnCo₂O₄上电荷分离效率提高、反应动力学改善、反应物吸附/活化促进以及中间产物转化加速的协同效应。一项对比研究表明，在反应过程中具有相同外部输入能量的情况下，Ru/MnCo₂O₄-2的催化效率远高于Ru/TiO₂和Ru/Al₂O₃。这项研究强调了光热载体所起的关键作用，并有望激发人们对锚定在光热底物上的等离子体金属纳米颗粒在温和条件下用于CO₂甲烷化的更高兴趣。
