Photocatalytic ethene synthesis from ethane dehydrogenation with high selectivity by ZnO-supported Pt nanoparticles†
Abstract
Thermal catalytic oxidative dehydrogenation of ethane with O2 has been extensively studied as an approach for ethene production, but this approach is energy intensive and has disadvantages of overoxidation, high-cost and safety concerns. Herein, we present ZnO-supported Pt nanoparticles that are highly active and selective for dehydrogenating ethane to ethene with simulated sunlight via a photo-supported Mars–van Krevelen mechanism. The Pt/ZnO catalyst achieves a high ethane-to-ethene conversion rate of 867.8 μmol h−1 g−1 and an excellent selectivity of 97.56%. Besides, it is also coking-resistant and can be readily revived by exposure to O2 for refilling the consumed lattice oxygen to preserve its original activity. It is revealed that the Pt species facilitate C2H4 desorption from the catalyst to inhibit overoxidation and enhance separation of light-induced charges to boost the photocatalytic efficiency. Whilst the photogenerated holes on ZnO are captured by surface lattice oxygen to generate active O˙− species, H atoms were extracted from adsorbed C2H6 to produce C2H4. In situ diffuse reflectance infrared Fourier transform spectroscopy is applied to detect the key intermediates and thus propose the possible catalytic EDH process over the Pt/ZnO photocatalyst.
- This article is part of the themed collection: Emerging Investigator Series