Surface cavities formed by molecularly rigid polymers of intrinsic microporosity affect catalytic processes. Palladium nanoparticles of typically 3 nm diameter are formed in an intrinsically microporous polyamine (PIM-EA-TB) by borohydride reduction. These particles are shown to indirectly catalyse the oxidative colour change of indicator dye 3,5,3′,5′-tetramethylbenzidine (TMB) in the presence of formic acid via formation of H₂O₂. Investigation reveals that oxygen reduction on the palladium is rate limiting with optimised H₂O₂ production at approximately pH 3 to 4, and first order in formate, followed by purely homogeneous TMB oxidation. The H₂O₂ production is therefore studied separately as a nanozyme-like catalytic process equivalent to formate oxidase reactivity, linked to the molecularly rigid polyamine host (PIM-EA-TB) providing ammonium sites (in molecularly rigid surface cavities) that enhance both (i) 2-electron formate oxidation and (ii) 2-electron oxygen reduction to H₂O₂. Beneficial effects of hydrophobic ClO₄^- anions are noted as indirect evidence for the effect of ammonium sites in surface cavities. A computational DFT model for the artificial formate oxidase reactivity is developed to underpin and illustrate the hypothesis of PIM-EA-TB as an active catalyst component with implications for future nanozyme sensor development.

由固有微孔隙的分子刚性聚合物形成的表面空腔影响催化过程。通过硼氢化物还原在固有微孔多胺 (PIM-EA-TB) 中形成直径通常为 3 nm 的钯纳米颗粒。这些颗粒显示在甲酸存在下通过形成 H ₂ O ₂间接催化指示剂染料 3,5,3',5'-四甲基联苯胺 (TMB) 的氧化变色。研究表明，钯上的氧还原是在大约 pH 3 至 4 下优化 H ₂ O ₂生成的速率限制，首先是甲酸盐，然后是纯均相 TMB 氧化。H ₂ O ₂因此，生产被单独研究为相当于甲酸氧化酶反应性的类似纳米酶的催化过程，连接到提供铵位点（在分子刚性表面空腔中）的分子刚性多胺宿主（PIM-EA-TB），增强（i）2-电子甲酸盐氧化和 (ii) 2-电子氧还原成 H ₂ O ₂。_{疏水性 ClO 4} ^-阴离子的有益效果被认为是表面空腔中铵位点影响的间接证据。开发了人工甲酸氧化酶反应性的计算 DFT 模型，以支持和说明 PIM-EA-TB 作为活性催化剂成分的假设，对未来纳米酶传感器的开发具有影响。