De Novo Design of a Pt Nanocatalyst on a Conjugated Microporous Polymer-Coated Honeycomb Carrier for Oxidation of Hydrogen Isotopes.

Abstract

A booming demand for energy highlights the importance of an emergency cleanup system in the nuclear industry or hydrogen-energy sector to reduce the risk of hydrogen explosion and decrease tritium emission. The properties of the catalyst determine the efficiency of hydrogen isotope enrichment and removal in the emergency cleanup system. However, the aggregation behavior of Pt, deactivation effect of water vapor, and isotope effect induce a continuous decrease in the catalytic activity of the Pt catalyst. Herein, a de novo design of a Pt nanocatalyst is proposed for catalytic oxidation of the hydrogen isotope via modification of a conjugated microporous polymer onto honeycomb cordierite as a Pt support. The conjugated microporous polymer creates a microporous and hydrophobic environment to attenuate the deactivation effect of water vapor and shape Pt nanoparticles with a diameter of around 2.4 nm. Thus, the as-prepared catalysts exhibit excellent catalytic performance in the range of 25-65 °C and high space velocity (≤30 000 h-1) and a stable and high catalytic activity during 487 h of continuous and intermittent operation. Importantly, the charge of the Pt nanoparticles is redistributed by the conjugated skeletons, leading to a decreased energy barrier in the rate-limiting step of hydrogen isotope oxidation and a reduced isotope effect.