The conversion of inert N_(2)and CO_(2)into urea by electrocatalytic technology not only reduces the cost of urea synthesis in future,but also alleviatesthe environmental pollution problem caused by carbon emission in...The conversion of inert N_(2)and CO_(2)into urea by electrocatalytic technology not only reduces the cost of urea synthesis in future,but also alleviatesthe environmental pollution problem caused by carbon emission in traditional industrial production.However,facing downside factors such as strong competitive reactions and unclear reaction mechanism,the design of high-performance urea catalysts is imminent.This study demonstrates that W_(18)O_(49)system doped heteronuclear metals(TM=Fe,Co,Ni)can effectively solve the problem of competitive adsorption between N_(2)and CO_(2)and realize the co-adsorption of N_(2)and CO_(2)at diverse sites.Their theoretical limiting voltages for urea production on TM-W_(18)O_(49)(TM=Fe,Co,Ni)systems are-0.46 V,-0.42 V and-0.52 V,respectively.The results are all lower than that of the contrastive voltage in pristine W_(18)O_(49)system(-0.91 V),further indicating the rationality and necessity of single-atom doped strategy for the co-reduction of two molecules.Specially,Co-W_(18)O_(49)can theoretically inhibit the side reactions of NRR,CO_(2)RR,and HER,which deserve future experimental exploration in future.The study suggests that doping heteronuclear metal into transition metal oxides is a feasible scheme to solve competitive adsorption and improve catalytic performance.展开更多
This study investigated if the addition of urea （U）, molasses （M） or their 1：1 （v/v） mixture during ensiling increases the nutritional value of forage from four fodder trees （Prunus persica, Leucaena esculenta...This study investigated if the addition of urea （U）, molasses （M） or their 1：1 （v/v） mixture during ensiling increases the nutritional value of forage from four fodder trees （Prunus persica, Leucaena esculenta, Acacia farnesiana, and Prunus domestica）. Forage samples of fodder trees were collected in triplicate （three individual samples of each species） and subjected to an in vitro gas production （GP） procedure. Fermentation at 24 h （GP 24）, short-chain volatile fatty acids （SCFA）, and microbial crude protein production （MCP）, in vitro organic matter digestibility （OMD）, metabolizable energy （ME） and dry matter degradability （DMD） were estimated. Forage samples were incubated for 72 h in an incubator at 39oC and the volume of GP was recorded at 2, 4, 6, 8, 10, 12, 24, 48, and 72 h of incubation using the reading pressure technique. The rumen fermentation profiles were highest for P. persica, which showed the highest （P〈0.0001） DMD, ME, OMD, SCFA, GP 24 and MCP. On the other hand L. esculenta had the lowest （P〈0.0001） DMD, SCFA, MCP; P. domestica had the lowest （P〈0.0001） OMD. The addition of M to silage increased （P〈0.0001） ME and OMD, as well as GP. However, the addition of U and the mixture of U and M reduced （P〈0.0001） DMD, ME, OMD, SCFA, GY 24 and MCP. These results show that P. persica has the highest nutritive value and L. esculenta the lowest for ruminants. Additionally, the addition of M to forage from fodder trees increases rumen GP and fermentation, which may improve nutrient utilization in ruminants.展开更多
电催化尿素氧化(UOR)替代动力学缓慢的析氧反应(OER)为高效制氢提供了新的思路。本研究通过简单的二次水热法制备了三维Ni_(3)S_(2)/NF微球催化剂(3D-Ni_(3)S_(2)/NF),由于独特的3D结构为UOR提供了高度开放的活性区域,并加快了电荷转移...电催化尿素氧化(UOR)替代动力学缓慢的析氧反应(OER)为高效制氢提供了新的思路。本研究通过简单的二次水热法制备了三维Ni_(3)S_(2)/NF微球催化剂(3D-Ni_(3)S_(2)/NF),由于独特的3D结构为UOR提供了高度开放的活性区域,并加快了电荷转移速率,3D-Ni_(3)S_(2)/NF表现出明显优于1D,2D-Ni_(3)S_(2)/NF电催化氧化尿素的活性。在1 mol L^(-1)KOH+0.33 mol L^(-1)尿素电解质溶液,3D-Ni_(3)S_(2)/NF电催化尿素氧化达到100 mA cm^(-2)的电流密度的电位仅需1.38 V vs.RHE,比OER电位减少了250 mV,同时在24 h稳定性测试中表现出良好的耐久性。此外,全尿素辅助制氢只需1.66 V即可达到50 mA cm^(-2),表现出比传统电解水(1.86 V)更低的电位。展开更多
基金The authors gratefully acknowledge financial support from the Youth Development Foundation of Jilin Province(No.20230508183RC)the National Natural Science Foundation of China(No.22403014,No.21673036)+2 种基金the China Postdoctoral Science Foundation(No.2023M730539,No.2024T170121)the Fundamental Research Funds for the Central Universities(No.2412022ZD050,No.2412023QD012)Some computations were carried out on TianHe-2 at LvLiang Cloud Computing Center of China.
文摘The conversion of inert N_(2)and CO_(2)into urea by electrocatalytic technology not only reduces the cost of urea synthesis in future,but also alleviatesthe environmental pollution problem caused by carbon emission in traditional industrial production.However,facing downside factors such as strong competitive reactions and unclear reaction mechanism,the design of high-performance urea catalysts is imminent.This study demonstrates that W_(18)O_(49)system doped heteronuclear metals(TM=Fe,Co,Ni)can effectively solve the problem of competitive adsorption between N_(2)and CO_(2)and realize the co-adsorption of N_(2)and CO_(2)at diverse sites.Their theoretical limiting voltages for urea production on TM-W_(18)O_(49)(TM=Fe,Co,Ni)systems are-0.46 V,-0.42 V and-0.52 V,respectively.The results are all lower than that of the contrastive voltage in pristine W_(18)O_(49)system(-0.91 V),further indicating the rationality and necessity of single-atom doped strategy for the co-reduction of two molecules.Specially,Co-W_(18)O_(49)can theoretically inhibit the side reactions of NRR,CO_(2)RR,and HER,which deserve future experimental exploration in future.The study suggests that doping heteronuclear metal into transition metal oxides is a feasible scheme to solve competitive adsorption and improve catalytic performance.
基金supported by the SEP (PROMEP), Mexico(PROMEP 103.5/09/4195)
文摘This study investigated if the addition of urea （U）, molasses （M） or their 1：1 （v/v） mixture during ensiling increases the nutritional value of forage from four fodder trees （Prunus persica, Leucaena esculenta, Acacia farnesiana, and Prunus domestica）. Forage samples of fodder trees were collected in triplicate （three individual samples of each species） and subjected to an in vitro gas production （GP） procedure. Fermentation at 24 h （GP 24）, short-chain volatile fatty acids （SCFA）, and microbial crude protein production （MCP）, in vitro organic matter digestibility （OMD）, metabolizable energy （ME） and dry matter degradability （DMD） were estimated. Forage samples were incubated for 72 h in an incubator at 39oC and the volume of GP was recorded at 2, 4, 6, 8, 10, 12, 24, 48, and 72 h of incubation using the reading pressure technique. The rumen fermentation profiles were highest for P. persica, which showed the highest （P〈0.0001） DMD, ME, OMD, SCFA, GP 24 and MCP. On the other hand L. esculenta had the lowest （P〈0.0001） DMD, SCFA, MCP; P. domestica had the lowest （P〈0.0001） OMD. The addition of M to silage increased （P〈0.0001） ME and OMD, as well as GP. However, the addition of U and the mixture of U and M reduced （P〈0.0001） DMD, ME, OMD, SCFA, GY 24 and MCP. These results show that P. persica has the highest nutritive value and L. esculenta the lowest for ruminants. Additionally, the addition of M to forage from fodder trees increases rumen GP and fermentation, which may improve nutrient utilization in ruminants.
文摘电催化尿素氧化(UOR)替代动力学缓慢的析氧反应(OER)为高效制氢提供了新的思路。本研究通过简单的二次水热法制备了三维Ni_(3)S_(2)/NF微球催化剂(3D-Ni_(3)S_(2)/NF),由于独特的3D结构为UOR提供了高度开放的活性区域,并加快了电荷转移速率,3D-Ni_(3)S_(2)/NF表现出明显优于1D,2D-Ni_(3)S_(2)/NF电催化氧化尿素的活性。在1 mol L^(-1)KOH+0.33 mol L^(-1)尿素电解质溶液,3D-Ni_(3)S_(2)/NF电催化尿素氧化达到100 mA cm^(-2)的电流密度的电位仅需1.38 V vs.RHE,比OER电位减少了250 mV,同时在24 h稳定性测试中表现出良好的耐久性。此外,全尿素辅助制氢只需1.66 V即可达到50 mA cm^(-2),表现出比传统电解水(1.86 V)更低的电位。
