Applications of Metal–Organic Frameworks and Their Derivatives in Electrochemical CO_(2)Reduction

Electrochemically reducing CO_(2)to more reduced chemical species is a promising way that not only enables the conversion of intermittent energy resources to stable fuels,but also helps to build a closed-loop anthropogenic carbon cycle.Among various electrocatalysts for electrochemical CO_(2)reduction,multifunctional metal–organic frameworks(MOFs)have been employed as highly efficient and selective heterogeneous electrocatalysts due to their ultrahigh porosity and topologically diverse structures.Up to now,great progress has been achieved in the design and synthesis of highly active and selective MOF-related catalysts for electrochemical CO_(2)reduction reaction(CO_(2)RR),and their corresponding reaction mechanisms have been thoroughly studied.In this review,we summarize the recent progress of applying MOFs and their derivatives in CO_(2)RR,with a focus on the design strategies for electrocatalysts and electrolyzers.We first discussed the reaction mechanisms for different CO_(2)RR products and introduced the commonly applied electrolyzer configurations in the current CO_(2)RR system.Then,an overview of several categories of products(CO,HCOOH,CH_(4),CH_(3)OH,and multi-carbon chemicals)generated from MOFs or their derivatives via CO_(2)RR was discussed.Finally,we offer some insights and perspectives for the future development of MOFs and their derivatives in electrochemical CO_(2)reduction.We aim to provide new insights into this field and further guide future research for large-scale applications.

Electrochemical CO_(2) reduction:Progress and opportunity with alloying copper

Electroreduction of carbon dioxide(CO_(2)) into value-added chemicals offers an entrancing approach to main-taining the global carbon cycle and eliminating environmental threats.A key obstacle to achieving long-term and large-scale implementation of electrochemical CO_(2) reduction technology is the lack of active and selective cat-alysts.Copper(Cu)is one of the few candidates that can facilitate C–C coupling to obtain high-energy oxygenates and hydrocarbons beyond carbon monoxide(CO),but it suffers from poor selectivity for products of interest and high overpotentials.Alloying is an effective way to break the linear scaling relations and uniquely manipulate the reactivity and selectivity,which is hard to achieve by using monometallic compositions alone.By alloying Cu with other metals,one could change the catalytic properties of the catalyst by tuning the local electronic structure and modulating the adsorption strength of the reaction intermediates,thus improving the catalytic activity and selectivity.In this review,we focus on the recently developed Cu-based alloy catalysts(including conventional alloys,high-entropy alloys and single-atom alloys)that have been applied in electrocatalytic CO_(2) reduction(ECR).Theoretical calculations and experimental advances in understanding the key rate-limiting and selectivity-determining steps in those alloys are summarized,with a particular focus on identifying binding energy de-scriptors and the dynamic product formation mechanisms.In addition,we outline the opportunities and chal-lenges in the fundamental understanding of ECR by recommending advanced in-situ characterization techniques and standardized electrochemical methods and offer atomic-level design principles for steering the reaction pathways to the desired products.

STX5 Inhibits Hepatocellular Carcinoma Adhesion and Promotes Metastasis by Regulating the PI3K/mTOR Pathway

Background and Aims:Syntaxin 5(STX5)is a member of the syntaxin or target-soluble SNAP receptor(t-SNARE)fam-ily and plays a critical role in autophagy.However,its function and molecular mechanism in tumor cell migration are still un-known.The role of STX5 in influencing hepatocellular carci-noma(HCC)is an important topic in our research.Methods:By using quantitative reverse transcription polymerase chain reaction(qPCR),western blotting,and immunohistochemical analysis of RNA and protein in tissues,we comprehensively evaluated data sets from public databases and clinical patient cohorts for STX5.The correlation of STX5 expression with the clinicopathological characteristics of HCC patients were assessed.In addition,we predicted signal pathways from dif-ferentially expressed genes(DEGs)and the Cancer Genome Atlas(TCGA)databases,and confirmed the prediction using integrated transcriptome and RNA-seq.We further investi-gated the underlying mechanisms of STX5 in the migration and adhesion of HCC cells both in vitro and in vivo.Results:In the TCGA dataset and our patient cohort,STX5 levels were significantly higher in HCC tissues than in adjacent normal liver tissues.At the same time,high expression of STX5 pre-dicted worse prognosis in patients with liver cancer.High ex-pression of STX5 indicates the decrease of adhesion and the increase of migration of HCC cells,and the conversion of epi-thelial-mesenchymal transition(EMT)in vitro via PI3K/mTOR pathway activation.Conversely,when Sirolimus,a phospho-inositide 3-kinase(PI3K)/AKT/mechanistic target of rapa-mycin(mTOR)inhibitor acts on cells simultaneously,STX5 overexpression-mediated enhancement of HCC metastasis is reversed.Double-negative regulation of STX5 and mTOR further enhanced the inhibitory effect of STX5 on HCC me-tastasis.In vivo,STX5 knockdown inhibited the metastasis of HCC cells.Conclusions:Our study demonstrates a novel research result that STX5 promotes HCC metastasis through PI3K/mTOR pathway.We believe that combined inhibition of STX5 and mTOR is a potential treatment for effectively pro-longing patient survival and inhibiting HCC metastasis.