State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX 77005, USA.
Sci Adv. 2023 Jun 16;9(24):eadg0167. doi: 10.1126/sciadv.adg0167.
The decomposition of cobalt carbide (CoC) to metallic cobalt in CO hydrogenation results in a notable drop in the selectivity of valued C products, and the stabilization of CoC remains a grand challenge. Here, we report an in situ synthesized K-CoC catalyst, and the selectivity of C hydrocarbons in CO hydrogenation achieves 67.3% at 300°C, 3.0 MPa. Experimental and theoretical results elucidate that CoO transforms to CoC in the reaction, while the stabilization of CoC is dependent on the reaction atmosphere and the K promoter. During the carburization, the K promoter and HO jointly assist in the formation of surface C species via the carboxylate intermediate, while the adsorption of C on CoO is enhanced by the K promoter. The lifetime of the K-CoC is further prolonged from 35 hours to over 200 hours by co-feeding HO. This work provides a fundamental understanding toward the role of HO in CoC chemistry, as well as the potential of extending its application in other reactions.
在 CO 加氢反应中，碳化钴（CoC）分解为金属钴会导致有价值的 C 产物选择性显著下降，而稳定 CoC 仍然是一个巨大的挑战。在这里，我们报告了一种原位合成的 K-CoC 催化剂，在 300°C、3.0 MPa 下，CO 加氢反应中 C 烃的选择性达到 67.3%。实验和理论结果表明，反应过程中 CoO 转化为 CoC，而 CoC 的稳定取决于反应气氛和 K 助剂。在碳化过程中，K 助剂和 HO 通过羧酸中间体能共同促进表面 C 物种的形成，而 K 助剂增强了 C 在 CoO 上的吸附。通过共进料 HO，K-CoC 的寿命从 35 小时延长到 200 小时以上。这项工作为理解 HO 在 CoC 化学中的作用以及将其应用于其他反应的潜力提供了基础。
