Advantages of Yolk Shell Catalysts for the DRM: A Comparison of Ni/ZnO@SiO2 vs. Ni/CeO2 and Ni/Al2O3

Precise Modulation of Triple‐Phase Boundaries towards a Highly Functional Exsolved Catalyst for Dry Reforming of Methane under a Dilution‐Free System

Dry reforming of methane (DRM) has been emerging as a viable solution to achieving carbon neutrality enhanced by the Paris Agreement as it converts the greenhouse gases of CO₂ and CH₄ into industrially useful syngas. However, there have been limited studies on the DRM catalyst under mild operating conditions with a high dilution gas ratio due to their deactivation from carbon coking and metal sintering. Herein, we apply the triple‐phase boundary (TPB) concept to DRM catalyst via exsolution phenomenon that can secure elongated TPB by controlling the Fe‐doping ratio in perovskite oxide. Remarkably, the exsolved catalyst with prolongated TPB shows exceptional CO₂ and CH₄ conversion rates of 95.9 % and 91.6 %, respectively, stable for 1000 hours under a dilution‐free system. DFT calculations confirm that the Lewis acid of support and Lewis base of metal at the TPB promote the adsorption of reactants, resulting in lowering the overall CO₂ dissociation and CH₄ dehydrogenation energy.

CeO2-Based Heterogeneous Catalysts in Dry Reforming Methane and Steam Reforming Methane: A Short Review

Transitioning to lower carbon energy and environment sustainability requires a reduction in greenhouse gases such as carbon dioxide (CO2) and methane (CH4) that contribute to global warming. One of the most actively studied rare earth metal catalysts is cerium oxide (CeO2) which produces remarkable improvements in catalysts in dry reforming methane. This paper reviews the management of CO2 emissions and the recent advent and trends in bimetallic catalyst development utilizing CeO2 in dry reforming methane (DRM) and steam reforming methane (SRM) from 2015 to 2021 as a way to reduce greenhouse gas emissions. This paper focus on the identification of key trends in catalyst preparation using CeO2 and the effectiveness of the catalysts formulated.

Engineering of Yolk/Core-Shell Structured Nanoreactors for Thermal Hydrogenations

Heterogeneous hydrogenation reactions are of great importance for chemical upgrading and synthesis, but still face the challenges of controlling selectivity and long-term stability. To improve the catalytic performance, many hydrogenation reactions utilize special yolk/core-shell nanoreactors (YCSNs) with unique architectures and advantageous properties. This work presents the developmental and technological challenges in the preparation of YCSNs that are potentially useful for hydrogenation reactions, and provides a summary of the properties of these materials. The work also addresses the scientific challenges in applications of these YCSNs in various gas and liquid-phase hydrogenation reactions. The catalyst structures, catalytic performance, structure-performance relationships, reaction mechanisms, and unsolved problems are discussed too. Also, a brief outlook and opportunities for future research in this field are presented. This work on the advancements in YCSNs might inspire the creation of new materials with desired structures for achieving maximal hydrogenation performances.

In Situ X-ray Microscopy Reveals Particle Dynamics in a NiCo Dry Methane Reforming Catalyst under Operating Conditions

Herein, we report the synthesis of a γ-Al₂O₃-supported NiCo catalyst for dry methane reforming (DMR) and study the catalyst using in situ scanning transmission X-ray microscopy (STXM) during the reduction (activation step) and under reaction conditions. During the reduction process, the NiCo alloy particles undergo elemental segregation with Co migrating toward the center of the catalyst particles and Ni migrating to the outer surfaces. Under DMR conditions, the segregated structure is maintained, thus hinting at the importance of this structure to optimal catalytic functions. Finally, the formation of Ni-rich branches on the surface of the particles is observed during DMR, suggesting that the loss of Ni from the outer shell may play a role in the reduced stability and hence catalyst deactivation. These findings provide insights into the morphological and electronic structural changes that occur in a NiCo-based catalyst during DMR. Further, this study emphasizes the need to study catalysts under operating conditions in order to elucidate material dynamics during the reaction.