Cu catalysts can convert CO_(2) through an electrochemical reduction reaction into a variety of useful carbon-based products.However,this capability provides an obstacle to increasing the selectivity for a single prod...Cu catalysts can convert CO_(2) through an electrochemical reduction reaction into a variety of useful carbon-based products.However,this capability provides an obstacle to increasing the selectivity for a single product.Herein,we report a simple fabrication method for a Cu-Pd alloy catalyst for use in a membrane electrode assembly(MEA)-based CO_(2) electrolyzer for the electrochemical CO_(2) reduction reaction(ECRR)with high selectivity for CO production.When the composition of the Cu-Pd alloy catalyst was fabricated at 6:4,the selectivity for CO increased and the production of multi-carbon compounds and hydrogen is suppressed.Introducing a Cu-Pd alloy catalyst with 6:4 ratio as the cathode of the MEAbased CO_(2) electrolyzer showed a CO faradaic efficiency of 92.8%at 2.4 V_(cell).We assumed that these results contributed from the crystal planes on the surface of the Cu-Pd alloy.The phases of the Cu-Pd alloy catalyst were partially separated through annealing to fabricate a catalyst with high selectivity for CO at low voltage and C_(2)H_4 at high voltage.The results of CO-stripping testing confirmed that when Cu partially separates from the lattice of the Cu-Pd alloy,the desorption of~*CO is suppressed,suggesting that C-C coupling reaction is favored.展开更多
Lakes act as one of the reservoirs and dispersal routes of antibiotic resistance genes(ARGs)and pathogenic resistant bacteria in aquatic environments.Previous studies reported the occurrence and distribution of ARGs i...Lakes act as one of the reservoirs and dispersal routes of antibiotic resistance genes(ARGs)and pathogenic resistant bacteria in aquatic environments.Previous studies reported the occurrence and distribution of ARGs in lakes worldwide;however,few investigated the biogeography and diversity patterns of antibiotic resistome in the environment.To fill this gap,a large-scale data set of sediment metagenomes was collected from globally distributed lakes and characterized comprehensively using metagenomic assembly-based analysis,aiming to shed light on the biogeography and diversity patterns of ARGs in lake ecosystems from a global perspective.Our analyses showed that abundant and diverse ARGs were found in the global lake sediments,including a set of emerging ARGs such as mcr-type and carbapenem-resistant Enterobacteriaceae related genes.Most of the identified ARGs were generally associated with the commonly used antibiotics,suggesting the role of increasing antibiotic consumptions on the resistome prevalence.Spatially,the composition and diversity of ARGs varied across geographical distances and exhibited a scale-dependent distancedecay relationship.Notably,the composition of ARGs was largely shaped by bacterial community structure,and their diversities were co-governed by stochastic process(∼48%)and deterministic process(∼52%).Findings provide a valuable insight to better understand ecological mechanisms of ARGs in lake ecosystems and have important implication for the prevention and control of resistome risk.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government MSIT(2021R1A2C2093358,2021R1A4A3027878,2022M3I3A1081901)financial support from the Lotte Chemical Company。
文摘Cu catalysts can convert CO_(2) through an electrochemical reduction reaction into a variety of useful carbon-based products.However,this capability provides an obstacle to increasing the selectivity for a single product.Herein,we report a simple fabrication method for a Cu-Pd alloy catalyst for use in a membrane electrode assembly(MEA)-based CO_(2) electrolyzer for the electrochemical CO_(2) reduction reaction(ECRR)with high selectivity for CO production.When the composition of the Cu-Pd alloy catalyst was fabricated at 6:4,the selectivity for CO increased and the production of multi-carbon compounds and hydrogen is suppressed.Introducing a Cu-Pd alloy catalyst with 6:4 ratio as the cathode of the MEAbased CO_(2) electrolyzer showed a CO faradaic efficiency of 92.8%at 2.4 V_(cell).We assumed that these results contributed from the crystal planes on the surface of the Cu-Pd alloy.The phases of the Cu-Pd alloy catalyst were partially separated through annealing to fabricate a catalyst with high selectivity for CO at low voltage and C_(2)H_4 at high voltage.The results of CO-stripping testing confirmed that when Cu partially separates from the lattice of the Cu-Pd alloy,the desorption of~*CO is suppressed,suggesting that C-C coupling reaction is favored.
基金supported by the Beijing Natural Science Foundation of China(No.8222059)the Major Science and Technology Program for Water Pollution Control and Treatment of China(No.2017ZX07302)+1 种基金the 111 Project of China(No.B18006)Beijing Advanced Innovation Program for Land Surface Science.
文摘Lakes act as one of the reservoirs and dispersal routes of antibiotic resistance genes(ARGs)and pathogenic resistant bacteria in aquatic environments.Previous studies reported the occurrence and distribution of ARGs in lakes worldwide;however,few investigated the biogeography and diversity patterns of antibiotic resistome in the environment.To fill this gap,a large-scale data set of sediment metagenomes was collected from globally distributed lakes and characterized comprehensively using metagenomic assembly-based analysis,aiming to shed light on the biogeography and diversity patterns of ARGs in lake ecosystems from a global perspective.Our analyses showed that abundant and diverse ARGs were found in the global lake sediments,including a set of emerging ARGs such as mcr-type and carbapenem-resistant Enterobacteriaceae related genes.Most of the identified ARGs were generally associated with the commonly used antibiotics,suggesting the role of increasing antibiotic consumptions on the resistome prevalence.Spatially,the composition and diversity of ARGs varied across geographical distances and exhibited a scale-dependent distancedecay relationship.Notably,the composition of ARGs was largely shaped by bacterial community structure,and their diversities were co-governed by stochastic process(∼48%)and deterministic process(∼52%).Findings provide a valuable insight to better understand ecological mechanisms of ARGs in lake ecosystems and have important implication for the prevention and control of resistome risk.
