Understanding the fundamental catalytic principles when the catalytic centre is confined in nanoscale space that is dimensionally comparable to the reactant molecule is crucial for designing high-performance catalysts. Theoretical studies with simplified model systems and ensemble experimental measurements have shown that chemical reactions in nanoconfined environments are largely different from those in bulk solution. Here, we design a well-defined platform with catalytic centres confined in the end of nanopores with controlled lengths to study the in situ dynamic behaviour of catalytic processes under nanoconfinement at the single-molecule and single-particle level. Variable single molecular mass transport behaviour reveals the heterogeneity of the confined environment in the nanopores. With the capability of decoupling mass transport factors from reaction kinetics in the well-defined platform, we quantitatively uncovered a confinement-induced enhancement in the activity of platinum nanoparticles inside the nanopores. The combination of the unique model catalyst and the single-molecule super-localization imaging technique paves the way to understanding nanoconfinement effects in catalysis.

当设计尺寸可与反应物分子相比的纳米级催化中心时，了解基本的催化原理至关重要，这对于设计高性能催化剂至关重要。用简化的模型系统和整体实验测量进行的理论研究表明，纳米密闭环境中的化学反应与本体溶液中的化学反应有很大不同。在这里，我们设计了一个定义明确的平台，该平台的催化中心限制在纳米孔的末端，长度可控，以研究在纳米约束下单分子和单粒子水平下催化过程的原位动力学行为。可变的单分子传质行为揭示了纳米孔中封闭环境的异质性。借助在定义明确的平台中将传质因子与反应动力学脱钩的能力，我们定量地发现了纳米孔内部铂纳米颗粒活性的局限性诱导增强。独特的模型催化剂和单分子超定位成像技术的结合为理解纳米约束作用在催化中铺平了道路。