Anti-CO poisoning ability is significant in formic acid oxidation in the fuel cell technique.Herein,Pd Ni alloy supported on N-doped graphene aerogel(Pd Ni/GA-N)was found to have catalytic ability toward formic acid e...Anti-CO poisoning ability is significant in formic acid oxidation in the fuel cell technique.Herein,Pd Ni alloy supported on N-doped graphene aerogel(Pd Ni/GA-N)was found to have catalytic ability toward formic acid electrooxidation over a wide potential range because of the improved anti-CO poisoning ability.This catalyst was fabricated by simple freeze-drying of mixture solution of graphene aerogel,polyvinylpyrrolidone,Pd^(2+)and Ni^(2+)and the subsequent thermal annealing reduction approach in the N2/H2 atmosphere.Pd-Ni alloy particles anchored over the folding N-doped graphene surface with a porous hierarchical architecture structure in the 3 D directions.It showed the catalytic performance of its maximum mass activity of 836 m A mg^(-1)in a broad potential range(0.2-0.6 V)for formic acid oxidation.The CO stripping experiment demonstrated its largely improved anti-CO poisoning ability with the peak potential of 0.67 V,approximately 60 and 40 m V less compared to those of Pd/GA-N and Pd/C samples.The high anti-CO poisoning ability and strong electronic effect resulting from the interaction between the3 D GA-N support and the Pd-Ni alloy makes it a promising catalyst for application in direct formic acid fuel cells.展开更多
Performance boosting of hybrid metal oxide and metal alloy catalyst is crucial to the water electrolysis for hydrogen generation. Herein, a novel concept of selective fluoridation of metal alloy/oxide hybrid is propos...Performance boosting of hybrid metal oxide and metal alloy catalyst is crucial to the water electrolysis for hydrogen generation. Herein, a novel concept of selective fluoridation of metal alloy/oxide hybrid is proposed to boost their catalytic performance for the oxygen evolution reaction(OER). A well-recognized OER catalyst system of FeNi3 alloy/oxide embedded in nitrogen-doped porous nanofibers(FeNiO/NCF) is employed as a proof of concept, and it is selectively fluoridated by transforming the metal oxide to metal fluoride(FeNiF/NCF). The crystal structure and surface chemical state transformation are well supported by the spectroscopic analysis and the improved electrochemical performance for OER can be well correlated to the phase and structure change. Specifically, FeNiF/NCF can drive the benchmark current density of 10 mA cm-2 at 260 mV with a Tafel slope of 67 mV dec-1, about 70 mV less than that of FeNiO/NCF.Increased catalytic kinetics, rapid charge transfer ability, high catalytic efficiency and stability are also probed by electrochemical analysis. The high surface area and roughness are found mainly generated via the high-temperature annealing for the metal alloy/metal oxide formation, and the low-temperature fluoridation process intrinsically contributes to the active structure formation. It is an efficient and universal approach to increase the catalytic performance of metal alloy/oxide for energy-relevant catalytic reactions.展开更多
Automatic infographics generators employ machine learning algorithms/user-defined rules and visual embellishments into the creation of infographics.It is an emerging topic in the field of information visualization tha...Automatic infographics generators employ machine learning algorithms/user-defined rules and visual embellishments into the creation of infographics.It is an emerging topic in the field of information visualization that has requirements in many sectors,such as dashboard design,data analysis,and visualization recommendation.The growing popularity of visual analytics in recent years brings increased attention to automatic infographics.This creates the need for a broad survey that reviews and assesses the significant advances in this field.Automatic tools aim to lower the barrier for visually analyzing data by automatically generating visualizations for analysts to search and make a choice,instead of manually specifying.This survey reviews and classifies automatic tools and papers of visualization recommendations into a set of application categories including networkgraph visualizations,annotation visualizations,and storytelling visualization.More importantly,this report presents several challenges and promising directions for future work in the field of automatic infographics and visualization recommendations.展开更多
基金supported by the National Natural Science Foundation of China(21972124,21603041)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institution+1 种基金the Double Tops Joint Fund of the Yunnan Science and Technology Bureau and Yunnan University(2019FY003025)the Research Foundation of Department of Education of Yunnan Province(2020Y0018)。
文摘Anti-CO poisoning ability is significant in formic acid oxidation in the fuel cell technique.Herein,Pd Ni alloy supported on N-doped graphene aerogel(Pd Ni/GA-N)was found to have catalytic ability toward formic acid electrooxidation over a wide potential range because of the improved anti-CO poisoning ability.This catalyst was fabricated by simple freeze-drying of mixture solution of graphene aerogel,polyvinylpyrrolidone,Pd^(2+)and Ni^(2+)and the subsequent thermal annealing reduction approach in the N2/H2 atmosphere.Pd-Ni alloy particles anchored over the folding N-doped graphene surface with a porous hierarchical architecture structure in the 3 D directions.It showed the catalytic performance of its maximum mass activity of 836 m A mg^(-1)in a broad potential range(0.2-0.6 V)for formic acid oxidation.The CO stripping experiment demonstrated its largely improved anti-CO poisoning ability with the peak potential of 0.67 V,approximately 60 and 40 m V less compared to those of Pd/GA-N and Pd/C samples.The high anti-CO poisoning ability and strong electronic effect resulting from the interaction between the3 D GA-N support and the Pd-Ni alloy makes it a promising catalyst for application in direct formic acid fuel cells.
基金supported by the National Natural Science Foundation of China (21603041 and 21972124)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionthe support of Six Talent Peaks Project of Jiangsu Province (XCL-070-2018)。
文摘Performance boosting of hybrid metal oxide and metal alloy catalyst is crucial to the water electrolysis for hydrogen generation. Herein, a novel concept of selective fluoridation of metal alloy/oxide hybrid is proposed to boost their catalytic performance for the oxygen evolution reaction(OER). A well-recognized OER catalyst system of FeNi3 alloy/oxide embedded in nitrogen-doped porous nanofibers(FeNiO/NCF) is employed as a proof of concept, and it is selectively fluoridated by transforming the metal oxide to metal fluoride(FeNiF/NCF). The crystal structure and surface chemical state transformation are well supported by the spectroscopic analysis and the improved electrochemical performance for OER can be well correlated to the phase and structure change. Specifically, FeNiF/NCF can drive the benchmark current density of 10 mA cm-2 at 260 mV with a Tafel slope of 67 mV dec-1, about 70 mV less than that of FeNiO/NCF.Increased catalytic kinetics, rapid charge transfer ability, high catalytic efficiency and stability are also probed by electrochemical analysis. The high surface area and roughness are found mainly generated via the high-temperature annealing for the metal alloy/metal oxide formation, and the low-temperature fluoridation process intrinsically contributes to the active structure formation. It is an efficient and universal approach to increase the catalytic performance of metal alloy/oxide for energy-relevant catalytic reactions.
基金National Natural Science Foundation of China(No.61972356,61902350)Zhejiang Provincial Natural Science Foundation of China(NO.LY19F020026)+1 种基金Zhejiang Provincial Key Research and Development Program of China(No.2019C01009)Fundamental Research Funds for the Provincial Universities of Zhejiang(NO.RF-C2019001).
文摘Automatic infographics generators employ machine learning algorithms/user-defined rules and visual embellishments into the creation of infographics.It is an emerging topic in the field of information visualization that has requirements in many sectors,such as dashboard design,data analysis,and visualization recommendation.The growing popularity of visual analytics in recent years brings increased attention to automatic infographics.This creates the need for a broad survey that reviews and assesses the significant advances in this field.Automatic tools aim to lower the barrier for visually analyzing data by automatically generating visualizations for analysts to search and make a choice,instead of manually specifying.This survey reviews and classifies automatic tools and papers of visualization recommendations into a set of application categories including networkgraph visualizations,annotation visualizations,and storytelling visualization.More importantly,this report presents several challenges and promising directions for future work in the field of automatic infographics and visualization recommendations.
