Ammonia is a promising platform molecule for the future renewable energy infrastructure owing to its high energy density (when liquefied) and carbon‐free nature. In particular, the interconversion ...between the chemical and electrical energies leveraging the nitrogen cycle could be an effective approach in mitigating the intermittency of renewable electricity production. However, efficient methods to store and release energy into and from ammonia, respectively, are still under development. Here, the latest developments in electrochemical ammonia synthesis and ammonia fuel cells are presented, and perspectives in the technical challenges and possible remedies are outlined. N2 electrolysis, plasma‐enabled N2 activation, and electro‐thermochemical looping are three potential approaches for electrochemical ammonia synthesis; however, achieving high selectivity and energy efficiency remains challenging. Direct ammonia fuel cells are suitable for a broad range of mobile and transportation applications but are limited by the lack of active catalysts for ammonia oxidation.
Ammonia is a promising platform molecule in the future renewable energy landscape. However, breakthroughs in catalyst development are needed to enable efficient and renewable production and utilization of ammonia. Significant recent developments in electrochemical synthesis via N2 electrolysis and utilization via ammonia fuel cells are summarized, and perspectives on this topic are given.
Light, inexpensive, effective: Nanostructured Co₃O₄ clusters (see picture) in mesoporous silica are the first example of a nanometer-sized multielectron catalyst made of a first-row transition-metal ...oxide that evolves oxygen from water efficiently. The nanorod bundle structure of the catalyst results in a very large surface area, an important factor contributing to the high turnover frequency.
Liver injury is common in patients with COVID‐19, but little is known about its clinical presentation and severity in the context of liver transplant. We describe a case of COVID‐19 in a patient who ...underwent transplant 3 years ago for hepatocellular carcinoma. The patient came to clinic with symptoms of respiratory disease; pharyngeal swabs for severe acute respiratory syndrome coronavirus 2 were positive. His disease progressed rapidly from mild to critical illness and was complicated by several nosocomial infections and multiorgan failure. Despite multiple invasive procedures and rescue therapies, he died from the disease. The management of COVID‐19 in the posttransplant setting presents complex challenges, emphasizing the importance of strict prevention strategies.
This report presents the clinic features, treatment, and fatal outcome in a liver transplant recipient with COVID‐19.
Metal oxide-modified biochar showed excellent adsorption performance in wastewater treatment. Iron nitrate and potassium permanganate were oxidative modifiers through which oxygen-containing groups ...and iron–manganese oxides could be introduced into biochar. In this study, iron–manganese (Fe–Mn) oxide-modified biochar (BC-FM) was synthesized using rice straw biochar, and the adsorption process, removal effect, and the mechanism of cadmium (Cd) adsorption on BC-FM in wastewater treatment were explored through batch adsorption experiments and characterization (SEM, BET, FTIR, XRD, and XPS). Adsorption kinetics showed that the maximum adsorption capacity of BC-FM for Cd(II) was 120.77 mg/g at 298 K, which was approximately 1.5–10 times the amount of adsorption capacity for Cd(II) by potassium-modified or manganese-modified biochar as mentioned in the literature. The Cd(II) adsorption of BC-FM was well fit by the pseudo-second-order adsorption and Langmuir models, and it was a spontaneous and endothermic process. Adsorption was mainly controlled via a chemical adsorption mechanism. Moreover, BC-FM could maintain a Cd removal rate of approximately 50% even when reused three times. Cd(II) capture by BC-FM was facilitated by coprecipitation, surface complexation, electrostatic attraction, and cation-π interaction. Additionally, the loaded Fe–Mn oxides also played an important role in the removal of Cd(II) by redox reaction and ion exchange in BC-FM. The results suggested that BC-FM could be used as an efficient adsorbent for treating Cd-contaminated wastewater.
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•A highly adsorptive Fe–Mn oxide-modified biochar was prepared using Fe(NO)3 and KMnO4.•The form and valence of Fe2O3 and Mn2O3 in BC-FM changed during Cd(II) adsorption.•BC-FM showed high removal capacity even reused three times (45.4%–66.2%).•Cu and Zn inhibited Cd(II) adsorption by competing for adsorption sites.
Abstract
The electroreduction of carbon dioxide offers a promising avenue to produce valuable fuels and chemicals using greenhouse gas carbon dioxide as the carbon feedstock. Because industrial ...carbon dioxide point sources often contain numerous contaminants, such as nitrogen oxides, understanding the potential impact of contaminants on carbon dioxide electrolysis is crucial for practical applications. Herein, we investigate the impact of various nitrogen oxides, including nitric oxide, nitrogen dioxide, and nitrous oxide, on carbon dioxide electroreduction on three model electrocatalysts (i.e., copper, silver, and tin). We demonstrate that the presence of nitrogen oxides (up to 0.83%) in the carbon dioxide feed leads to a considerable Faradaic efficiency loss in carbon dioxide electroreduction, which is caused by the preferential electroreduction of nitrogen oxides over carbon dioxide. The primary products of nitrogen oxides electroreduction include nitrous oxide, nitrogen, hydroxylamine, and ammonia. Despite the loss in Faradaic efficiency, the electrocatalysts exhibit similar carbon dioxide reduction performances once a pure carbon dioxide feed is restored, indicating a negligible long-term impact of nitrogen oxides on the catalytic properties of the model catalysts.
The recent development of nanostructured electrocatalysts for CO2 reduction has attracted much attention because they exhibit unique properties compared to their bulk counterparts. In this ...minireview, the latest studies on electrocatalytic CO2 reduction with a focus on the advances of nanostructured metallic electrocatalysts are reviewed and discussed. The distinct catalytic properties and potential challenges of nanostructured electrocatalysts are summarized. The behavior of nanosized catalysts in ionic liquid electrolytes is also discussed. Ideas for the design of next‐generation electrocatalysts by taking the advantages of nanostructured materials are proposed.
Small is beautiful: Electrochemical CO2 reduction is an attractive approach to convert CO2 produced in power plants, refineries, and petrochemical plants to liquid fuels or useful chemicals. Recent progress in nanostructured metallic catalysts has exhibited tremendous promise for such realization. This review takes a closer look at those studies, and future research directions are proposed and discussed.
Vaccination is the most economic and effective measure to deal with infectious diseases and protect public health. Nowadays, due to the spread of COVID-19 and the ensuing pandemic, safe, effective ...vaccines are in urgent need. However, due to concerns about vaccine safety, there is still reluctance to vaccinate. In China, in response to the Changchun Changsheng Vaccine incident, the National People’s Congress Standing Committee passed the Vaccine Administration Law in 2019, which marks China’s first comprehensive piece of legislation on vaccine regulation. The law establishes a regulatory system covering the entire life cycle of vaccines, introduces the vaccine marketing authorization holder system, stipulates the legal responsibilities of all parties, and further clarifies the compensation system for any individuals who exhibit abnormal reactions to vaccination. In addition, it emphasizes the use of modern technology to build a national vaccine electronic platform for tracing. To balance vaccine efficacy and safety, it is necessary to further improve the vaccine risk management mechanism, promote cooperation between government and non-governmental actors, and avoid improper interventions in the vaccine market.
Despite significant efforts towards the direct conversion of syngas into liquid fuels, the selectivity remains a challenge, particularly with regard to high‐quality gasoline with a high octane number ...and a low content of aromatic compounds. Herein, we show that zeolites with 1D ten‐membered‐ring (10‐MR) channel structures such as SAPO‐11 and ZSM‐22 in combination with zinc‐ and manganese‐based metal oxides (ZnaMnbOx) enable the selective synthesis of gasoline‐range hydrocarbons C5–C11 directly from syngas. The gasoline selectivity reached 76.7 % among hydrocarbons, with only 2.3 % CH4 at 20.3 % CO conversion. The ratio of isoparaffins to n‐paraffins was as high as 15, and the research octane number was estimated to be 92. Furthermore, the content of aromatic compounds in the gasoline was as low as 16 %. The composition and structure of ZnaMnbOx play an important role in determining the overall activity. This process constitutes a potential technology for the one‐step synthesis of environmentally friendly gasoline with a high octane number from a variety of carbon resources via syngas.
The one‐step synthesis of high‐quality gasoline from syngas with a selectivity of 76.7 % among hydrocarbons is enabled by the combination of a ZnaMnbOx oxide with a zeolite with one‐dimensional ten‐membered‐ring channels, such as SAPO‐11 or ZSM‐22. The isoparaffin/n‐paraffin ratio reached 15, and the content of aromatic compounds was significantly below the limits set by most countries.
Syngas conversion by Fischer–Tropsch synthesis (FTS) is characterized by a wide distribution of hydrocarbon products ranging from one to a few carbon atoms. Reported here is that the product ...selectivity is effectively steered toward ethylene by employing the oxide‐zeolite (OX‐ZEO) catalyst concept with ZnCrOx‐mordenite (MOR). The selectivity of ethylene alone reaches as high as 73 % among other hydrocarbons at a 26 % CO conversion. This selectivity is significantly higher than those obtained in any other direct syngas conversion or the multistep process methanol‐to‐olefin conversion. This highly selective pathway is realized over the catalytic sites within the 8‐membered ring (8MR) side pockets of MOR via a ketene intermediate rather than methanol in the 8MR or 12MR channels. This study provides substantive evidence for a new type of syngas chemistry with ketene as the key reaction intermediate and enables extraordinary ethylene selectivity within the OX‐ZEO catalyst framework.
Deep pockets: The eight‐membered‐ring side pockets of mordenite can effectively steer the conversion of ketene intermediates, formed over ZnCrOx during syngas conversion, toward ethylene with a selectivity of 73 % at a CO conversion of 26 %. By comparison, methanol intermediates are mainly converted over the 12‐membered‐ring sites of MOR and result in a remarkably different product distribution dominated by longer‐chain hydrocarbons.
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