Immobilized Tetraalkylammonium Cations Enable Metal-free CO2 Electroreduction in Acid and Pure Water.

Carbon dioxide reduction reaction (CO2 RR) provides an efficient pathway to convert CO2 into desirable products, yet its commercialization is greatly hindered by the huge energy cost due to CO2 loss and regeneration. Performing CO2 RR under acidic conditions containing alkali cations can potentially address the issue, but still causes (bi)carbonate deposition at high current densities, compromising product Faradaic efficiencies (FEs) in present-day acid-fed membrane electrode assemblies. Herein, we present a strategy using a positively charged polyelectrolyte-poly(diallyldimethylammonium) immobilized on graphene oxide via electrostatic interactions to displace alkali cations. This enables a FE of 85 %, a carbon efficiency of 93 %, and an energy efficiency (EE) of 35 % for CO at 100 mA cm-2 on modified Ag catalysts in acid. In a pure-water-fed reactor, we obtained a 78 % CO FE with a 30 % EE at 100 mA cm-2 at 40 °C. All the performance metrics are comparable to or even exceed those attained in the presence of alkali metal cations.

Post-COVID pain and quality of life in COVID-19 patients: protocol for a meta-analysis and systematic review.

INTRODUCTION: During the COVID-19 pandemic, approximately 10%-35% of COVID-19 infected patients experience post-COVID sequela. Among these sequelae, pain symptoms should not be neglected. In addition, the sequelae of COVID-19 also decrease the quality of life of these populations. However, meta-analyses that systematically evaluated post-COVID pain are sparse. METHODS AND ANALYSIS: A comprehensive screening will be performed by searching MEDLINE and Embase without language restriction from inception to August 2021. Cohort studies, case-control studies, cross-sectional studies and case series will be included. Case report and interventional studies will be excluded. Studies with less than 20 participants will be also excluded. We aim to investigate the prevalence of pain-related symptoms in patients after the acute phase of COVID-19. The impact of COVID-19 on the quality of life and pain symptoms among these populations in the post-acute phase will also be evaluated. ROBINS-I tool will be used to assess the risk of bias of cohort studies. The risk of bias tool developed by Hoy et al will be used to assess the risk of bias of prevalence studies. Metaprop command in Stata will be used to estimate the pooled prevalence of pain symptoms. DerSimonian and Laird random-effects models will be used to calculate the pooled relative risks. All analyses will be calculated using Stata software (V.15.0; StataCorp) ETHICS AND DISSEMINATION: Ethics approval is not required. Results of our study will be submitted to a peer-review journal. PROSPERO REGISTRATION NUMBER: CRD42021272800.

Ultrafine Pd Nanoparticles Supported on Soft Nitriding Porous Carbon for Hydrogen Production from Hydrolytic Dehydrogenation of Dimethyl Amine-Borane.

Simple and efficient synthesis of a nano-catalyst with an excellent catalytic property for hydrogen generation from hydrolysis of dimethyl amine-borane (DMAB) is a missing piece. Herein, effective and recycled palladium (Pd) nanoparticles (NPs) supported on soft nitriding porous carbon (NPC) are fabricated and applied for DMAB hydrolysis. It is discovered that the soft nitriding via a low-temperature urea-pretreatment induces abundant nitrogen-containing species on the NPC support, thus promoting the affinity of the Pd precursor and hindering the agglomeration of formed Pd NPs onto the NPC surface during the preparation process. Surface-clean Pd NPs with a diameter of sub-2.0 nm deposited on the NPC support (Pd/NPC) exhibit an outstanding catalytic performance with a turnover frequency (TOF) of 2758 h-1 toward DMAB hydrolysis, better than many previous reported Pd-based catalysts. It should be emphasized that the Pd/NPC also possesses a good stability without an obvious decrease in catalytic activity for DMAB hydrolysis in five successive recycling runs. This study provides a facile but efficient way for preparing high-performance Pd catalysts for catalytic hydrogen productions.