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Non-thermal plasma activation promotes CO2 conversion over Ni catalysts supported on BETA zeolite via multiple reaction mechanisms.

ZSM-5 zeolite nanoboxes with accessible mesomicro-pore architecture and strong acid sites are important in relevant heterogeneous catalysis suffering from mass transfer limitations and weak acidities.R ational design of parent zeolites with concentrated and non-protective coordination of Al species can facilitate post-synthetic treatment to produce mesoporous ZSM-5 nanoboxes.I nt his work, as imple and effective method was developed to convert parent MFI zeolites with tetrahedral extra-framework Al into Al-enriched mesoporous ZSM-5 nanoboxes with low silicon-to-aluminium ratios of % 16. The parent MFI zeolite was prepared by rapid ageing of the zeolite sol gel synthesis mixture.The accessibility to the meso-micro-porous intra-crystalline network was probed systematically by comparative pulsed field gradient nuclear magnetic resonance diffusion measurements,w hich, together with the strong acidity of nanoboxes,provided superb catalytic activity and longevity in hydrocarbon cracking for propylene production.

A systematic study of Ni supported on metal-organic frameworks (MOFs) catalyst (i.e., 15Ni/UiO-66) for catalytic CO 2 hydrogenation under nonthermal plasma (NTP) conditions was presented. The catalyst outperformed other catalysts based on conventional supports such as ZrO 2 , representing highest CO 2 conversion and CH 4 selectivity at about 85 and 99%, respectively. We found that the turnover frequency of the NTP catalysis system (1.8 ± 0.02 s −1) has a nearly twofold improvement compared with the thermal catalysis (1.0 ± 0.06 s −1). After 20 hr test, XPS and HRTEM characterizations confirmed the stability of the 15Ni/UiO-66 catalyst in the NTPactivated catalysis. The activation barrier for the NTP-activated catalysis was calculated as~32 kJ mol −1 , being lower than the activation energy of the thermal catalysis (~70 kJ mol −1). In situ DRIFTS characterization confirmed the formation of multiple carbonates and formates on catalyst surface activated by NTP, surpassing the control catalysts (e.g., 15Ni/α-Al 2 O 3 and 15Ni/ZrO 2).