An effective oxygen electrode based on Ir0.6Sn0.4O2 for PEM water electrolyzers

An effective oxygen evolution electrode with Ir0.6Sn0.4O2 was designed for proton exchange membrane(PEM)water electrolyzers.The anode catalyst layer exhibits a jagged structure with smaller particles and pores,which provide more active sites and mass transportation channels.The prepared IrSn electrode showed a cell voltage of 1.96 V at 2.0 A cm^-2 with Ir loading as low as 0.294 mg cm^-2.Furthermore,Ir Sn electrode with different anode catalyst loadings was investigated.The IrS n electrode indicates higher mass current and more stable cell voltage than the commercial Ir Black electrode at low loading.

SuPoolVisor:a visual analytics system for mining pool surveillance

Cryptocurrencies represented by Bitcoin have fully demonstrated their advantages and great potential in payment and monetary systems during the last decade.The mining pool,which is considered the source of Bitcoin,is the cornerstone of market stability.The surveillance of the mining pool can help regulators effectively assess the overall health of Bitcoin and issues.However,the anonymity of mining-pool miners and the difficulty of analyzing large numbers of transactions limit in-depth analysis.It is also a challenge to achieve intuitive and comprehensive monitoring of multi-source heterogeneous data.In this study,we present SuPoolVisor,an interactive visual analytics system that supports surveillance of the mining pool and de-anonymization by visual reasoning.SuPoolVisor is divided into pool level and address level.At the pool level,we use a sorted stream graph to illustrate the evolution of computing power of pools over time,and glyphs are designed in two other views to demonstrate the influence scope of the mining pool and the migration of pool members.At the address level,we use a force-directed graph and a massive sequence view to present the dynamic address network in the mining pool.Particularly,these two views,together with the Radviz view,support an iterative visual reasoning process for de-anonymization of pool members and provide interactions for cross-view analysis and identity marking.Effectiveness and usability of SuPoolVisor are demonstrated using three cases,in which we cooperate closely with experts in this field.

Ti_(4)O_(7) supported IrO_(x) for anode reversal tolerance in proton exchange membrane fuel cell

Fuel starvation can occur and cause damage to the cell when proton exchange membrane fuel cells operate under complex working conditions.In this case,carbon corrosion occurs.Oxygen evolution reaction(OER)catalysts can alleviate carbon corrosion by introducing water electrolysis at a lower potential at the anode in fuel shortage.The mixture of hydrogen oxidation reaction(HOR)and unsupported OER catalyst not only reduces the electrolysis efficiency,but also influences the initial performance of the fuel cell.Herein,Ti_(4)O_(7) supported IrO_(x) is synthesized by utilizing the surfactant-assistant method and serves as reversal tolerant components in the anode.When the cell reverse time is less than 100 min,the cell voltage of the MEA added with IrO_(x)/Ti_(4)O_(7) has almost no attenuation.Besides,the MEA has a longer reversal time(530 min)than IrO_(x)(75 min),showing an excellent reversal tolerance.The results of electron microscopy spectroscopy show that IrO_(x) particles have a good dispersity on the surface of Ti_(4)O_(7) and IrO_(x)/Ti_(4)O_(7) particles are uniformly dispersed on the anode catalytic layer.After the stability test,the Ti_(4)O_(7) support has little decay,demonstrating a high electrochemical stability.IrO_(x)/Ti_(4)O_(7) with a high dispersity has a great potential to the application on the reversal tolerance anode of the fuel cell.