Zhang Junyan, Li Yuanyuan, Song Haohong, Zhang Lihua, Wu Yiqing, He Yang, Ma Lu, Hong Jiyun, Tayal Akhil, Marinkovic Nebojsa, Jiang De-En, Li Zhenglong, Wu Zili, Polo-Garzon Felipe
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
Interdisciplinary Materials Science, Vanderbilt University, Nashville, TN, USA.
Nat Commun. 2024 Oct 3;15(1):8566. doi: 10.1038/s41467-024-50729-8.
Ni-based catalysts are highly reactive for dry reforming of methane (DRM) but they are prone to rapid deactivation due to sintering and/or coking. In this study, we present a straightforward approach for anchoring dispersed Ni sites with strengthened metal-support interactions, which leads to Ni active sites embedded in dealuminated Beta zeolite with superior stability and rates for DRM. The process involves solid-state grinding of dealuminated Beta zeolites and nickel nitrate, followed by calcination under finely controlled gas flow conditions. By combining in situ X-ray absorption spectroscopy and ab initio simulations, it is elucidated that the efficient removal of byproducts during catalyst synthesis is conducted to strengthen Ni-Si interactions that suppress coking and sintering after 100 h of time-on-stream. Transient isotopic kinetic experiments shed light on the differences in intrinsic turnover frequency of Ni species and explain performance trends. This work constructs a fundamental understanding regarding the implication of facile synthesis protocols on metal-support interaction in zeolite-supported Ni sites, and it lays the needed foundations on how these interactions can be tuned for outstanding DRM performance.
镍基催化剂对甲烷干重整（DRM）具有高反应活性，但由于烧结和/或积碳，它们易于快速失活。在本研究中，我们提出了一种直接的方法来锚定分散的镍位点，增强金属-载体相互作用，从而使镍活性位点嵌入脱铝β沸石中，具有卓越的稳定性和DRM反应速率。该过程包括将脱铝β沸石和硝酸镍进行固态研磨，然后在精细控制的气流条件下进行煅烧。通过结合原位X射线吸收光谱和从头算模拟，阐明了在催化剂合成过程中有效去除副产物以增强镍-硅相互作用，从而在100小时的反应时间后抑制积碳和烧结。瞬态同位素动力学实验揭示了镍物种本征周转频率的差异，并解释了性能趋势。这项工作构建了关于简便合成方案对沸石负载镍位点中金属-载体相互作用的影响的基本理解，并为如何调整这些相互作用以实现出色的DRM性能奠定了所需的基础。
