Highly Efficient Decomposition of Perfluorocarbons for over 1000 Hours via Active Site Regeneration

Abstract

Tetrafluoromethane (CF4), the simplest perfluorocarbon (PFC), has the potential to exacerbate global warming. Catalytic hydrolysis is a viable method to degrade CF4, but fluorine poisoning severely restricts both the catalytic performance and catalyst lifetime. In this study, Ga is introduced to effectively assists the defluorination of poisoned Al active sites, leading to highly efficient CF4 decomposition at 600°C with a catalytic lifetime exceeding 1,000 hours. 27Al and 71Ga magic‐angle spinning nuclear magnetic resonance spectroscopy (MAS NMR) showed that the introduced Ga exists as tetracoordinated Ga sites (GaIV), which readily dissociate water to form Ga–OH. In‐situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density function theory (DFT) calculations confirmed that Ga–OH assists the defluorination of poisoned Al active sites via a dehydration‐like process. As a result, the Ga/Al2O3 catalyst achieved 100% CF4 decomposition keeping an ultra‐long catalytic lifetime and outperforming reported results. This work proposes a new approach for efficient and long‐term CF4 decomposition by promoting the regeneration of active sites.

An efficient Ni3S2–Ni electrode constructed by a one-step powder metallurgy approach for the hydrogen evolution reaction

“…With the continuous depletion of non-renewable fossil fuels and increasing environmental pollution, finding green and renewable energy sources to replace fossil energy is critical to future energy sustainability and the global environment. 1–3 Hydrogen energy is considered to be an attractive sustainable energy with high mass energy density and zero-carbon nature. 4–7 Hydrogen production is an essential part of hydrogen energy.…”

Promoted CF4 Decomposition via Enhanced Tricoordinated Al Active Sites

“…At present, various methods, including plasma, combustion, and catalytic hydrolysis, have been developed for the decomposition methods of CF 4 . − Among them, catalytic hydrolysis is regarded as a promising method owing to its capability of high decomposition efficiency and large gas flux. − Al-based materials with abundant acidic sites are the most used catalysts in decomposition of CF 4 . − Song et al reported that the more the Lewis acid sites on the surface of Al-based catalysts, the stronger the ability to decompose CF 4 . Zhang et al found that the strong Lewis acid site of unsaturated tricoordinated Al (Al III ) was the main active site for CF 4 decomposition, indicating that more Al III active sites represent higher CF 4 decomposition activity.…”

Reconstruction of Bi2S3 in CO2 Electroreduction via Topotactic Transformation

“…The extensive use of fossil fuels, such as coal, oil, and natural gas, has led to increased carbon dioxide emissions, resulting in significant environmental issues such as land desertification, sea level rise, and climate change. − To address this challenge, converting CO 2 into fuels or high-value chemicals has been suggested as an ideal way to mitigate CO 2 emissions. − Among various techniques, electrocatalytic CO 2 reduction reaction (CO 2 RR) has been identified as one of the most efficient and controllable methods, − as it reduces not only CO 2 emissions but also human dependence on fossil fuels by utilizing low-grade renewable electricity . However, the CO 2 RR requires high energy to activate the nonpolar and chemically inert linear CO 2 molecule with CO bonds under ambient conditions. − Additionally, the competition of hydrogen evolution reaction (HER) in aqueous CO 2 RR solution poses challenges to controlling product selectivity. , …”