Related Articles

Site-designed dual-active-center catalysts for co-catalysis in advanced oxidation processes

Advanced Oxidation Processes (AOPs) are promising for treating persistent pollutants, yet challenges arise due to the step-wise oxidants activation process, which traditional single-active-center catalysts struggle to facilitate effectively. Recently, dual-active-center catalysts have emerged as a solution by enabling synergistic reactions. This review covers advances in these catalysts, their co-catalytic mechanisms, and applications in electro-Fenton, photocatalytic, peroxymonosulfate-, and pollutant-as-electron-donor based Fenton-like processes, along with active site design considerations and future challenges.

Bank lending and environmental quality in Gulf Cooperation Council countries

To achieve economies with net-zero carbon emissions, it is essential to develop a robust green financial intermediary channel. This study seeks empirical evidence on how domestic bank lending to sovereign and private sectors in Gulf Cooperation Council (GCC) countries impacts carbon dioxide and greenhouse gas emissions. We employ PMG-ARDL model to panel data comprising six countries in GCC over twenty years for carbon dioxide emissions and nineteen years for greenhouse gas emissions. Our findings reveal a long-term positive impact of both bank lending variables on carbon dioxide and greenhouse gas emissions. In addition, lending to the government shows a negative short-term effect on greenhouse gas emissions. The cross-country results demonstrate the presence of a long-run effect of explanatory variables on both types of emissions, except for greenhouse gas in Saudi Arabia. The sort-term impact of the explanatory variables on carbon dioxide and greenhouse gas emissions is quite diverse. Not only do these effects differ across countries, but some variables have opposing effects on the two types of emissions within a single country. The findings of this study present a new perspective for GCC economies: neglecting total greenhouse gas emissions and concentrating solely on carbon dioxide emissions means missing critical information for devising effective strategies to combat threats of environmental degradation and achieve net-zero goals.

Effects of nitrogen vacancy sites of oxynitride support on the catalytic activity for ammonia decomposition

Nitrogen-containing compounds such as imides and amides have been reported as efficient materials that promote ammonia decomposition over nonnoble metal catalysts. However, these compounds decompose in an air atmosphere and become inactive, which leads to difficulty in handling. Here, we focused on perovskite oxynitrides as air-stable and efficient supports for ammonia decomposition catalysts. Ni-loaded oxynitrides exhibited 2.5–18 times greater catalytic activity than did the corresponding oxide-supported Ni catalysts, even without noticeable differences in the Ni particle size and surface area of the supports. The catalytic performance of the Ni-loaded oxynitrides is well correlated with the nitrogen desorption temperature during N2 temperature-programmed desorption, which suggests that the lattice nitrogen in the oxynitride support rather than the Ni surface is the active site for ammonia decomposition. Furthermore, NH3 temperature-programmed surface reactions and density functional theory (DFT) calculations revealed that NH3 molecules are preferentially adsorbed on the nitrogen vacancy sites on the support surface rather than on the Ni surface. Thus, the ammonia decomposition reaction is facilitated by a vacancy-mediated reaction mechanism.

Floating 3D-PDMS-Iron oxide molecular baskets for decontaminating diverse pollutants and analyzing structural composition impacts

Novel iron oxide-incorporated porous polydimethylsiloxane sponges were developed using a simple, non-toxic two-step process. Characterized through various techniques, these sponges serve as effective photocatalysts, absorbents, and adsorbents for pollutant removal. They demonstrated nearly 100% degradation of rhodamine B under optimal conditions ( ~ 100% with Xe arc lamp, 50 mg, pH 3-9, and 4 h), following a pseudo second-order kinetic model (r2 = 0.9999). The sponges also exhibited good activity for other pollutants, including methylene blue (76–87%), 1,4-dichlorobenzene (57–71%), and azithromycin (82–87%), and maintained high performance over 11 reuse cycles with minimal iron loss. In addition, fresh and used catalysts effectively separated oils (173–680 mg with 50 mg of absorbent, and 10–15 s) and chromium (VI) [~87% with 1 ppm, 50 mg, pH 7, and 24 h] from water. This environmentally sustainable approach produces no toxic waste and allows for simple regeneration, making it a promising solution for the water treatment industry.

Mechanisms of electrochemical hydrogenation of aromatic compound mixtures over a bimetallic PtRu catalyst

Efficient electrochemical hydrogenation (ECH) of organic compounds is essential for sustainability, promoting chemical feedstock circularity and synthetic fuel production. This study investigates the ECH of benzoic acid, phenol, guaiacol, and their mixtures, key components in upgradeable oils, using a carbon-supported PtRu catalyst under varying initial concentrations, temperatures, and current densities. Phenol achieved the highest conversion (83.17%) with a 60% Faradaic efficiency (FE). In mixtures, benzoic acid + phenol yielded the best performance (64.19% conversion, 74% FE), indicating a synergistic effect. Notably, BA consistently exhibited 100% selectivity for cyclohexane carboxylic acid (CCA) across all conditions. Density functional theory (DFT) calculations revealed that parallel adsorption of BA on the cathode (−1.12 eV) is more stable than perpendicular positioning (-0.58 eV), explaining the high selectivity for CCA. These findings provide a foundation for future developments in ECH of real pyrolysis oil.

Responses

Your email address will not be published. Required fields are marked *