Detailed thermodynamic analysis was utilized to decouple the complex reaction network of CO2-mediated oxidative dehydrogenation (CO2-ODH) of propane and unravel critical catalyst design requirements. Inspired by the unmatched ability of boron-based catalysts in limiting cracking and overoxidation reaction pathways, we exploited controlled integration of both VOx and BOx active phases onto a γ-Al2O3 support and constructed a highly efficient CO2-ODH catalyst via scalable mechanochemical synthesis route. The solvent- and template-free synthetic design strategy regulated crucial properties of the catalysts and endowed suitable site diversity as evidenced from N2-adsorption analysis, XRD, HRTEM, Raman analysis, NH3-TPD, H2-TPR, and UV–Vis diffuse reflectance spectroscopy. Consequently, excellent propane conversion and propylene yield of 61 and 34 % respectively over 12 h time on stream (TOS) at 650 °C were realized with a catalyst composed of 5 wt% vanadium and 7 wt% boron. In situ DRIFT measurement revealed insight into the dynamic changes on the catalyst surface and the corresponding evolution of reaction intermediates during the CO2-ODH process. Overall, the thermodynamic investigation re-emphasized the critical importance of effective kinetic control while the synthetic protocol illustrated a promising avenue for rational design of CO2-ODH catalysts to harness the unique advantages of boron and metal oxide-based catalysts simultaneously.

中文翻译：

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解偶联反应网络并设计具有合适位点多样性的稳健VOx/Al2O3催化剂，以促进CO2介导的丙烷氧化脱氢


利用详细的热力学分析来解耦 CO2 介导的丙烷氧化脱氢 (CO2-ODH) 的复杂反应网络，并阐明关键的催化剂设计要求。受硼基催化剂在限制裂化和过氧化反应途径方面无与伦比的能力的启发，我们利用 VOx 和 BOx 活性相在 γ-Al2O3 载体上的受控整合，并通过可扩展的机械化学合成路线构建了高效的 CO2-ODH 催化剂。 N2 吸附分析、XRD、HRTEM、拉曼分析、NH3-TPD、H2-TPR 和 UV-Vis 漫反射表明，无溶剂和无模板的合成设计策略调节了催化剂的关键性能，并赋予了适当的位点多样性光谱学。因此，使用由 5 wt% 钒和 7 wt% 硼组成的催化剂，在 650 °C 下运行 12 小时 (TOS) 时，丙烷转化率和丙烯收率分别达到 61% 和 34%。原位 DRIFT 测量揭示了 CO2-ODH 过程中催化剂表面的动态变化以及反应中间体的相应演变。总体而言，热力学研究再次强调了有效动力学控制的至关重要性，而合成方案则展示了合理设计 CO2-ODH 催化剂以同时利用硼和金属氧化物基催化剂的独特优势的一条有前途的途径。