The Langmuir-Hinshelwood formalism describes catalytic reactions of Langmuirian surface species under the assumption that all adsorbates are randomly-distributed – enabling adjacency of surface-bound intermediates to be determined solely by coverages of single-site occupants. We demonstrate herein that this approximation is inappropriate even for simple catalytic reactions (e.g. A + A → A₂) and manifestly neglects islanding of slowly-consumed species and partitioning of highly-reactive species inherently engendered by ≥two-site elementary steps (e.g. A*–A* → A_2(g) + *–*). Rigorous description of kinetically-consequential islanding/partitioning phenomena requires explicit description of the coverage and chemical dynamics of all multi-site ensembles. Higher-order, ensemble-specific rate terms identify the particular microscopic events relevant to each ensemble, and, in doing so, reveal that each elementary step (e.g. A_(g) adsorption) describes not one event (e.g. A_(g) + * → A*) , but a sum over all ensemble-specific paths (e.g. A_(g) + *–* → A*–* and A_(g) + A*–* → A*–A*). De-convoluting each elementary step into its constituent multi-site paths proffers kinetic detail otherwise inaccessible – enabling (i) identification of rate- and selectivity-determining site ensembles, (ii) calculation of rates and degrees of rate control of ensemble-specific elementary steps, (iii) incorporation of adsorbate surface diffusion, (iv) incorporation of lateral adsorbate interactions, and (v) quantitative description of catalysis of multi-site-occupying intermediates (e.g. *C_nH_m* species in hydrocarbon (de-)hydrogenation and C-C bond coupling/cleavage reactions) which we demonstrate is inaccessible to the Langmuir-Hinshelwood formalism even if adsorbate surface diffusion is infinitely-fast.

Langmuir-Hinshelwood 形式主义描述了 Langmuir 表面物种的催化反应，假设所有吸附物都是随机分布的 - 使表面结合中间体的相邻性仅由单点居住者的覆盖范围决定。我们在此证明，即使对于简单的催化反应（例如A + A → A ₂），这种近似也是不合适的，并且明显忽略了缓慢消耗物种的孤岛化和由≥双位点基本步骤（例如A *– A * → A _2(g)+ *–*）。对动力学结果孤岛/分区现象的严格描述需要对所有多站点集合的覆盖范围和化学动力学进行明确描述。更高阶的、特定于集合的速率项识别与每个集合相关的特定微观事件，并在这样做时揭示每个基本步骤（例如A _(g)吸附）描述的不是一个事件（例如A _(g) + * → A *) ，但对所有特定于集成的路径求和（例如A _(g) + *–* → A *–* 和A _(g) + A *–* → A *– A*）。将每个基本步骤解卷积为其组成的多站点路径提供了否则无法访问的动力学细节——能够 (i) 识别速率和选择性决定站点集合，(ii) 计算速率和集合特定元素的速率控制程度步骤，（iii）吸附物表面扩散的结合，（iv）横向吸附物相互作用的结合，以及（v）多位点占据中间体（例如* C _n H _m *碳氢化合物中的物种（de-）的催化的定量描述）氢化和C - C键偶联/裂解反应）我们证明，即使吸附质表面扩散无限快，Langmuir-Hinshelwood 形式主义也无法达到这一点。