Particle size is an important parameter of supported catalysts, but understanding the size-performance relationship is a challenge, especially in some complicated process. In this contribution, the particle size effect on CO₂ hydrogenation to hydrocarbons over iron-based catalysts was deconvoluted into the effects on primary and secondary reactions. With a particle size range of 2.5–12.9 nm, the overall selectivity of C₂+ hydrocarbons increases continuously, while that of CO decreases with the increasing size. The reverse water gas shift (RWGS) reaction and methanation are the main primary reactions and they are more sensitive within a particle size range of 6.1–12.9 nm. The formation of formate species is more favored, and thereby more CH₄ is produced as a primary product on larger particles. The secondary process, the further hydrogenation of primary CO to hydrocarbons, is more sensitive within the particle size range of 2.5–9.8 nm, where the geometric effect or ensemble effect on larger particles leads to a higher chain-growth probability. More terrace sites may be conducive for C–C coupling, and the enhanced CO adsorption also benefits the secondary process. These findings highlight the deconvoluted particle size effect on CO₂ hydrogenation and provide a dimension for understanding the catalysts in complicated reaction networks.

中文翻译：

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铁基催化剂上的粒径反卷积对CO ₂加氢的影响

粒度是负载型催化剂的重要参数，但了解粒度与性能的关系是一个挑战，尤其是在某些复杂的过程中。在这种贡献中，粒度对铁基催化剂上CO ₂加氢成烃的影响被分解为对一级和二级反应的影响。在2.5-12.9 nm的粒径范围内，C ₂ +碳氢化合物的总选择性不断增加，而CO的总选择性随粒径的增加而降低。反向水煤气变换（RWGS）反应和甲烷化是主要的主要反应，它们在6.1-12.9 nm的粒径范围内更为敏感。甲酸类物质的形成更受青睐，因此有更多的CH ₄在较大的颗粒上作为主要产品生产。第二个过程是将初级CO进一步氢化为烃，在2.5-9.8 nm的粒径范围内更为敏感，其中较大颗粒的几何效应或整体效应导致链增长的可能性更高。更多的平台部位可能有利于CC耦合，并且增加的CO吸附也有利于二次工艺。这些发现凸显了去卷积的粒度对CO ₂加氢的影响，并为理解复杂反应网络中的催化剂提供了一个维度。