Introducing transition metals into CuAlO spinel enhances catalyst stability and Cu sintering resistance in methanol steam reforming. Yet, the influence of doping on vacancy formation and the adsorption behaviors of CO (the primary product) and CO (the notorious byproduct) remains unclear. Herein, we employed DFT + U to investigate CO and CO adsorption on perfect, M-doped (Fe, Co, and Ni), and M-doped oxygen-deficient CuAlO spinel (100) and (110) surfaces. We find that stronger CO adsorption on (100) than (110) surfaces across all M-doped surfaces, while CO adsorbs more stronger on (110) surfaces. The weakened CO adsorptions are observed on Fe and Ni-doped surfaces, demonstrating that doping plays a significant role in improving the resistance to CO poisoning. Co-doping promotes CO adsorption via a CO-like structure on CuAlO(110) surface and boosts the CO oxidation. Furthermore, infrared spectroscopy simulation indicates that the vibrational frequencies for CO linear adsorption, formation of bent CO- and CO-like structures are within the ranges of 2042–2078, 1463–1566, and 1497–1816 cm, respectively. In addition, Ov on Ni-doped surfaces can significantly strengthen the CO adsorption by 0.6–1.3 eV, highlighting the doping and oxygen-defect engineering in enhancing the CO capture. This research uncovers the critical impact of metal doping and oxygen vacancies on CO and CO adsorptions over CuAlO spinel catalyst, providing insights for developing catalysts with improved resistance to CO poisoning and enhanced CO oxidation which is vital for methanol steam reforming.

中文翻译：

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DFT 深入了解掺杂和氧空位对 CuAl2O4 尖晶石表面 CO 和 CO2 吸附的影响


在 CuAlO 尖晶石中引入过渡金属可提高甲醇水蒸气重整催化剂的稳定性和 Cu 的抗烧结性。然而，掺杂对空位形成以及 CO（初级产物）和 CO（臭名昭著的副产物）吸附行为的影响仍不清楚。在此，我们采用 DFT + U 来研究 CO 和 CO 在完美、M 掺杂（Fe、Co 和 Ni）和 M 掺杂缺氧 CuAlO 尖晶石 (100) 和 (110) 表面上的吸附。我们发现，在所有 M 掺杂表面上，(100) 表面上的 CO 吸附比 (110) 表面上的吸附更强，而 (110) 表面上的 CO 吸附更强。在 Fe 和 Ni 掺杂表面观察到 CO 吸附减弱，表明掺杂在提高抗 CO 中毒能力方面发挥着重要作用。共掺杂通过 CuAlO(110) 表面上的类 CO 结构促进 CO 吸附，并促进 CO 氧化。此外，红外光谱模拟表明，CO 线性吸附、弯曲 CO 和类 CO 结构形成的振动频率分别在 2042-2078、1463-1566 和 1497-1816 cm 范围内。此外，Ni掺杂表面上的Ov可以显着增强CO吸附0.6-1.3 eV，突出了掺杂和氧缺陷工程在增强CO捕获方面的作用。这项研究揭示了金属掺杂和氧空位对 CuAlO 尖晶石催化剂上 CO 和 CO 吸附的关键影响，为开发具有更高抗 CO 中毒能力和增强 CO 氧化能力的催化剂提供了见解，这对于甲醇蒸汽重整至关重要。