Embedded catalysts prepared by grinding crystallization and their catalytic performance in dry reforming of methane: Domain-limited nanostructures for high activity and stability
Jicheng Zhu, Dan Yang, Yi Lu, Yin Li, Qixin Yang, Jing Di, Haoquan Liang, Yingyun Qiao, Yuanyu Tian, Xikun Gai
Abstract
Dry reforming of methane (DRM) takes advantage of greenhouse gases (CH 4 and CO 2 ) and mitigates their eco-environmental consequences. However, the biggest obstacle for DRM reactions has been the design of catalysts with high resistance to sintering and carbon deposition. In this paper, the embedded bimetallic nickel-cobalt@ silicalite-1 (S1) catalysts (NiCo@S1), with high resistance to sintering and lower carbon deposition, were prepared by grinding crystallization method. The physicochemical characterizations demonstrated that the embedded catalyst for NiCo@S1 could effectively control the size and dispersion of the active metal Ni–Co in the catalyst compared to the supported catalysts for 10Ni/SiO 2 and 10Ni/S1, which further enhance the interaction between the active metal phase and the carrier S1, and greatly minimize the amount of carbon accumulation on the catalysts. After being subjected to a reaction at 700 °C for 6 h, the 10Ni2.5Co@S1 exhibited a significant performance improvement. The instantaneous conversion rate of CH 4 increased from 63.17% to 86.39% (an increase of 23.22%), and the instantaneous conversion rate of CO 2 rose from 70.20% to 88.62% (an increase of 18.42%). Additionally, carbon deposition reduced from 14.58% to 0.82% (a decrease of 13.76%). Therefore, the conceptual design provided a new perspective for designing Ni-based dry reforming catalysts.