Xu Kai, Zhang Yuan-Yi, Wang Wei-Wei, Peng Mi, Liu Jin-Cheng, Ma Chao, Zhang Ya-Wen, Jia Chun-Jiang, Ma Ding, Yan Chun-Hua
Key Laboratory for Colloid and Interface Chemistry, Key Laboratory of Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, China.
College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing, China.
Angew Chem Int Ed Engl. 2025 Jan 21;64(4):e202416195. doi: 10.1002/anie.202416195. Epub 2024 Nov 18.
As a well-established topic, single-atom catalyst has drawn growing interest for its high utilization of metal. However, researchers prefer to develop various active metals with single-atom form, the intrinsic roles of single-atom promoters are usually underrated, which are significant in boosting reaction activity. In this work, Ba single atoms were in situ prepared in the Co-Ba/YO catalyst with crystallized BaCO as the precursor under the ammonia decomposition reaction condition. The optimized Co-Ba/YO catalyst achieves extremely high H production rate of 138.3 mmolH ⋅ g ⋅ min at very low temperature (500 °C, GHSV=840,000 mL ⋅ g ⋅ h) and Co-Ba/YO exhibits excellent durability during the 350 h test, which realizes the highest activity among all non-noble catalysts, and reaches or even exceeds numerous reported Ru-based catalysts. Both YO and Co demonstrate positive interactions with Ba, which significantly facilitates the dispersion of Ba species at high temperatures (≥600 °C). Ba single atoms significantly enhance the charge density of Co and form additionally active Co-O-Ba-YO interfacial sites, which alleviates hydrogen poisoning and decreases the reaction barrier of the N-H bond activation of *NH. The exploration of atomically dispersed promoters is groundbreaking in heterogeneous catalysis, which opens up a whole new domain of catalytic material.
作为一个成熟的研究课题，单原子催化剂因其对金属的高利用率而越来越受到关注。然而，研究人员倾向于开发各种单原子形式的活性金属，单原子助剂的内在作用通常被低估，而这些作用在提高反应活性方面具有重要意义。在这项工作中，以结晶碳酸钡为前驱体，在氨分解反应条件下原位制备了钴钡/氧化钇催化剂中的钡单原子。优化后的钴钡/氧化钇催化剂在非常低的温度（500°C，气体时空速=840,000 mL·g·h）下实现了极高的产氢速率，为138.3 mmolH·g·min，并且钴钡/氧化钇在350小时的测试中表现出优异的耐久性，这使其在所有非贵金属催化剂中实现了最高活性，甚至达到或超过了许多已报道的钌基催化剂。氧化钇和钴都与钡表现出正相互作用，这显著促进了钡物种在高温（≥600°C）下的分散。钡单原子显著提高了钴的电荷密度，并形成了额外的活性钴-氧-钡-氧化钇界面位点，这减轻了氢中毒并降低了*NH的N-H键活化反应势垒。对原子分散助剂的探索在多相催化中具有开创性意义，为催化材料开辟了一个全新的领域。
