对用于捕获和活化CO2的廉价活性材料的寻找导致了许多旨在开发新催化剂的努力。在这种情况下,地球丰富的过渡金属碳化物(TMC)已经成为有希望的候选者,近几十年来,由于其特殊的耐火性能和耐烧结性,引起了越来越多的关注,焦化,硫磺中毒.在这项工作中,我们评估第5组TMC(VC,NBC,和TaC)作为碳捕获和封存/利用技术的潜在材料,通过结合实验表征技术,基于第一原理的多尺度建模,振动分析,和催化实验。我们的发现表明,VC的化学计量相表现出与CO2的弱相互作用,显示出无法吸附或解离它。然而,VC经常表现出表面碳空位的存在,导致CO2在室温下显著活化并促进其催化氢化。相比之下,化学计量的NbC和TaC相表现出与CO2更强的相互作用,能够在低温下吸附甚至破坏CO2,在TaC的情况下尤其值得注意。然而,NbC和TaC对CO2加氢表现出较差的催化性能。这项工作表明,第5组TMC是减排二氧化碳的潜在材料,强调了表面空位在增强催化活性和吸附能力方面的重要性,并为使用红外光谱作为唯一标识符来检测第5族TMC内的氧碳化物相或表面C空位提供了参考。
The search for cheap and active materials for the capture and activation of CO2 has led to many efforts aimed at developing new catalysts. In this context, earth-abundant transition metal carbides (TMCs) have emerged as promising candidates, garnering increased attention in recent decades due to their exceptional refractory properties and resistance to sintering, coking, and sulfur poisoning. In this work, we assess the use of Group 5 TMCs (VC, NbC, and TaC) as potential materials for carbon capture and sequestration/utilization technologies by combining experimental characterization techniques, first-principles-based multiscale modeling, vibrational analysis, and catalytic experiments. Our findings reveal that the stoichiometric phase of VC exhibits weak interactions with CO2, displaying an inability to adsorb or dissociate it. However, VC often exhibits the presence of surface carbon vacancies, leading to significant activation of CO2 at room temperature and facilitating its catalytic hydrogenation. In contrast, stoichiometric NbC and TaC phases exhibit stronger interactions with CO2, capable of adsorbing and even breaking of CO2 at low temperatures, particularly notable in the case of TaC. Nevertheless, NbC and TaC demonstrate poor catalytic performance for CO2 hydrogenation. This work suggests Group 5 TMCs as potential materials for CO2 abatement, emphasizes the importance of surface vacancies in enhancing catalytic activity and adsorption capability, and provides a reference for using the infrared spectra as a unique identifier to detect oxy-carbide phases or surface C vacancies within Group 5 TMCs.