北京大学马丁研究组的最新研究揭示，单原子钡助剂对氨分解的非贵金属催化剂有极大的增强作用。这一研究成果于2024年11月5日发表在国际顶尖学术期刊《德国应用化学》上。

在该工作中，在氨分解反应条件下，以结晶化的BaCO₃为前驱体，在Co-Ba/Y₂O₃催化剂上原位制备Ba单原子。优化后的Co-Ba/Y₂O₃催化剂H₂产率达到138.3 mmol　H₂·gcat^-1·min^-1在极低温度（500℃，GHSV = 840000 mL·g^-1·h^-1）下，Co-Ba/Y₂O₃在350 h的测试中表现出优异的耐久性，在所有非贵金属催化剂中实现了最高的活性，达到甚至超过了许多报道的Ru基催化剂。

在高温（≥600℃）条件下，Y₂O₃和Co与Ba均表现出正相互作用，有利于Ba的分散。Ba单原子显著提高Co的电荷密度，形成额外的活性Co-O-Ba-Y₂O₃界面位，减轻了氢中毒，降低了*NH的N-H键活化的反应势垒。原子分散助催化的探索在多相催化领域具有开创性意义，为催化材料开辟了一个全新的领域。

据介绍，单原子催化剂因其对金属的高利用率而受到越来越多的关注。然而，研究人员倾向于开发单原子形式的多种活性金属，单原子助催化的内在作用往往被低估，而这在提高反应活性方面具有重要作用。

附：英文原文

Title: Single-atom Barium Promoter Enormously Enhanced Non-noble Metal Catalyst for Ammonia Decomposition

Author: Kai Xu, Yuan-Yi Zhang, Wei-Wei Wang, Mi Peng, Jin-Cheng Liu, Chao Ma, Ya-Wen Zhang, Chun-Jiang Jia, Ding Ma, Chun-Hua Yan

Issue&Volume: 2024-11-05

Abstract: 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/Y2O3 catalyst with crystallized BaCO3 as the precursor under the ammonia decomposition reaction condition. The optimized Co-Ba/Y2O3 catalyst achieves extremely high H2 production rate of 138.3 mmolH2·gcat1·min1 at very low temperature (500 °C, GHSV = 840,000 mL·g1·h1) and Co-Ba/Y2O3 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 Y2O3 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-Y2O3 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.

DOI: 10.1002/anie.202416195

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202416195