Hydrogen Spillover Effect in Electrocatalysis:Delving into the Mysteries of the Atomic Migration

Hydrogen spillover effect has recently garnered a lot of attention in the field of electrocatalytic hydrogen evolution reactions.A new avenue for understanding the dynamic behavior of atomic migration in which hydrogen atoms moving on a catalyst surface was opened up by the setup of the word"hydrogen spillover."However,there is currently a dearth of thorough knowledge regarding the hydrogen spillover effect.Currently,the advancement of sophisticated characterization procedures offers progressively useful information to enhance our grasp of the hydrogen spillover effect.The understanding of material fabrication for hydrogen spillover effect has erupted.Considering these factors,we made an effort to review most of the articles published on the hydrogen spillover effect and carefully analyzed the aspect of material fabrication.All of our attention has been directed toward the molecular pathway that leads to improve hydrogen evolution reactions performance.In addition,we have attempted to elucidate the spillover paths through the utilization of DFT calculations.Furthermore,we provide some preliminary research suggestions and highlight the opportunities and obstacles that are still to be confronted in this study area.

Internal Polarization Field Induced Hydroxyl Spillover Effect for Industrial Water Splitting Electrolyzers

The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction(OER)are affinitive with hydroxyl adsorption.However,ability of the catalyst to capture hydroxyl and maintain the continuous supply at active sits remains a tremendous challenge.Herein,an affordable Ni2P/FeP2 heterostructure is presented to form the internal polarization field(IPF),arising hydroxyl spillover(HOSo)during OER.Facilitated by IPF,the oriented HOSo from FeP2 to Ni2P can activate the Ni site with a new hydroxyl transmission channel and build the optimized reaction path of oxygen intermediates for lower adsorption energy,boosting the OER activity(242 mV vs.RHE at 100 mA cm-2)for least 100 h.More interestingly,for the anion exchange membrane water electrolyzer(AEMWE)with low concentration electrolyte,the advantage of HOSo effect is significantly amplified,delivering 1 A cm^(-2)at a low cell voltage of 1.88 V with excellent stability for over 50 h.

Impact of digital economy development on carbon productivity:An empirical analysis based on threshold effect and spatial spillover effect

Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development and carbon productivity.The findings indicate that digital economic development significantly contributes to the enhancement of carbon productivity in the long term.Furthermore,through instrumental variable method,replacement of explanatory variables and other methods to test its endogeneity and stability,the results remain robust.In terms of regional heterogeneity,the impact of digital economic development on carbon productivity is less pronounced in the central and western regions compared to the eastern region.Additionally,further investigation reveals that industrial structure upgrading and science and technology investment level exhibit different threshold effects on the influence of digital economy development level on carbon productivity.Moreover,there is a significant spatial spillover effect of digital economy development on carbon productivity with H-H and L-L agglomeration spatial correlation.

Research on the Impact of China’s Foreign Trade Technology Spillover on Green Total Factor Productivity of Countries Along the“Belt and Road”:Based on the Institutional Quality Threshold Effect

China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model to empirically analyze the institutional quality threshold effect of China’s foreign trade technology spillover on the GTFP of countries along the“Belt and Road.”The results show that China’s foreign trade technology spillover has a significant institutional quality double threshold effect on the green total factor productivity of the countries along the“Belt and Road.”As the institutional quality of the countries along the“Belt and Road”crosses a specific threshold value,the impact of China’s foreign trade technology spillover on the green total factor productivity of the countries along the“Belt and Road”has a significant positive promoting effect,and corresponding suggestions are put forward.

Spatial spillover effects of transport infrastructure on regional economic growth

Spatial spillover effects,either positive or negative,of transport infrastructure,highways/expressways,etc.,on regional economic growth are proposed.Using the panel data for 11 cities of Zhejiang province from 1994 to 2003,a spatial production function is applied to examine the spatial spillovers which can be generated as a positive output spillover from the transport infrastructure between neighboring cities.Some spatial weighted matrices are adopted to define different neighboring cities to measure how easily factors or economic activities can migrate between regions.The estimation results show that the output elasticity of the highway infrastructure in 11 cities are all insignificant at a 5% significance level;hence,highway infrastructure in a region cannot explain the same region's economic growth.On the other hand,the highway infrastructure of other contiguous regions has positive spillover effects on a same region's economic growth.

Magic of hydrogen spillover: Understanding and application

The hydrogen spillover effect(HSPE)plays an important role in heterogeneous catalysis and hydrogen storage as an interfacial phenomenon,which facilitates the improvement of hydrogen storage properties of porous nanomaterials and indirectly or directly affects the reaction performance of multiphase catalytic reactions.The setting-up of the word“hydrogen spillover”opened up a new area to gain insight into the dynamic behavior of migrating hydrogen atoms on a catalyst surface.However,a comprehensive understanding of the HSPE is still lacking.Today,the development of advanced characterization techniques provides increasingly valuable information to further our understanding of the HSPE.Based on these considerations,in this review,we hope to provide some answers to the question“What is hydrogen spillover and how do we recognize it?”.To do this,we will rely on advanced characterization techniques as well as experimental and theoretical studies.Then,we discuss in detail the influences of the HSPE on hydrogen storage performance and the important catalytic effects of the HSPE in catalysis.These effects will be reviewed by looking through the catalytic results obtained in many reactions in thermal catalysis,electrocatalysis,and photocatalysis.Furthermore,based on the application potential of hydrogen spillover,we present some preliminary research proposals and discuss the opportunities and challenges that remain to be faced in this research area.

Method of spillover identification in urban street networks using loop detector outputs

Quick and reliable identification of the traffic state is of critical importance to traffic control systems, especially when spillovers appear. Firstly, a calculation method for the occupancy per cycle under different traffic conditions were presented, based on the relationship between the three basic traffic flow parameters, speed, traffic flow and density. Secondly, the times at which the stopping and starting waves approach a loop detector were confirmed using the traffic wave models modified by a kinematic equation. Then, the threshold of occupancy, which characterizes the appearance of spillovers, was determined by the premise that the stopping and starting waves had the same speed. At last, the accuracy and usability of the new method were verified by VISSIM simulation, using the ratio of misjudgment as the evaluation index. The results show that the ratio of misjudgment of the new method is about 11.36% compared to 17.65% of the previous method.

Spillover on a Platinum Electrode Modified by MWNTs

The spillover phenomenon is observed on the platinum (Pt) disk electrode modified bymulti-wall carbon nanotubes (MWNTs). The rate of the spillover of oxygen-containing speciesproduced on Pt surface to and from MWNTs is fast. However for hydrogen-adatoms, thespillover is very weak. The selective spillover on the Pt/MWNTs electrode may provide a novelway to design catalysts.

The Spillover Effect between Futures and Spot Price of Agricultural Products:A Case Study of Soybean Products of China

Taking soybean products as an example and using the daily price data of 2007-2015,this paper established the error correction model and BEKK-GARCH model,and made an empirical study on the spillover effect of futures and spot price of agricultural products of China. According to this study,there were mean spillover effect and two-way volatility spillover effect in futures and spot price of soybean,soybean oil,and soybean meal; soybean futures prices significantly guided the spot price; in the price linkage between the types,the price relationship between the soybean meal and soybean was closer than between the soybean oil and soybean.

Regime specific spillover across cryptocurrencies and the role of COVID‑19

The aim of this study is to examine the daily return spillover among 18 cryptocurrencies under low and high volatility regimes,while considering three pricing factors and the effect of the COVID-19 outbreak.To do so,we apply a Markov regime-switching(MS)vector autoregressive with exogenous variables(VARX)model to a daily dataset from 25-July-2016 to 1-April-2020.The results indicate various patterns of spillover in high and low volatility regimes,especially during the COVID-19 outbreak.The total spillover index varies with time and abruptly intensifies following the outbreak of COVID-19,especially in the high volatility regime.Notably,the network analysis reveals further evidence of much higher spillovers in the high volatility regime during the COVID-19 outbreak,which is consistent with the notion of contagion during stress periods.

A Comparison of Spillover Effects before, during and after the 2008 Financial Crisis

This paper applies graphical modelling to the S & P 500, Nikkei 225 and FTSE 100 stock market indices to trace the spillover of returns and volatility between these three major world stock market indices before, during and after the 2008 financial crisis. We find that the depth of market integration changed significantly between the pre-crisis period and the crisis and post-crisis period. Graphical models of both return and volatility spillovers are presented for each period. We conclude that graphical models are a useful tool in the analysis of multivariate time series where tracing the flow of causality is important.

Low-carbon technology innovation responding to climate change from the perspective of spatial spillover effects

China's technological efforts to tackle climate change have lasted for many years. It is necessary to test the effect of these efforts with quantitative method. To be exact, whether and how China's low-carbon technology innovation responds to climate change should be tested. Based on the2004-2015 panel data of 30 provinces in China, we use the method of ESDA analyzing the spatial correlation of China's low-carbon innovation technology. Furthermore, we use the spatial Durbin model empirically analyzing the spatial spillover effects. The results obtained are as follows: first,supply and demand of Chinese low-carbon innovation has some deviation in the spatial distribution. The low-carbon technology innovation as the supply factor shows the characteristics of expanding from the east to the west. Innovation in eastern China has always been the most active, but innovative activities in the middle and western China are gradually decreased.However, carbon emissions have the characteristics of moving westward, implying the change of technology demand different from technology supply. Second, China's low-carbon innovation actively responds to the trend of climate change, indicating China's technological efforts have paid off. However, the spatial spillover effects are not significant, showing that the efforts in each region of China still work for himself. Third, environmental regulation and market pull are important factors for low-carbon technology innovation. Among them, both supporting policy and inhibitory policy have significant impact on the local low-carbon technology innovation, but no significant spatial spillover effects. It shows that environmental policies in different regions are competitive and lack of demonstration effects. Economic growth and export as market pull have higher level of effect on low-carbon technology innovation for both local and adjacent areas.Some policy implications are proposed based on these results finally.

Dynamics of volatility spillover between stock market and foreign exchange market: evidence from Asian Countries

Background:The purpose of this study is to examine volatility spillover effects between stock market and foreign exchange market in selected Asian countries;Pakistan,India,Sri Lanka,China,Hong Kong and Japan.This study considered daily data from 4th January,1999 to 1st January,2014.Methods:This study opted EGARCH(Exponential Generalized Auto Regressive Conditional Heteroskedasticity)model for the purpose of analyzing asymmetric volatility spillover effects between stock and foreign exchange market.Results:The EGARCH analyses reveal bidirectional asymmetric volatility spillover between stock market and foreign exchange market of Pakistan,China,Hong Kong and Sri Lanka.The results reveal unidirectional transmission of volatility from stock market to foreign exchange market of India.The analysis reveals no evidence of volatility transmission between the two markets in reference to Japan.Conclusions:The result of this study provide valuable insights to economic policy makers for financial stability perspective and to investors regarding decision making in international portfolio and currency risk strategies.

Study on spillover effect of copper futures between LME and SHFE using wavelet multiresolution analysis

Research on information spillover effects between financial markets remains active in the economic community. A Granger-type model has recently been used to investigate the spillover between London Metal Exchange(LME) and Shanghai Futures Exchange(SHFE) ,however,possible correlation between the future price and return on different time scales have been ignored. In this paper,wavelet multiresolution decomposition is used to investigate the spillover effects of copper future returns between the two markets. The daily return time series are decomposed on 2n(n=1,…,6) frequency bands through wavelet mul-tiresolution analysis. The correlation between the two markets is studied with decomposed data. It is shown that high frequency detail components represent much more energy than low-frequency smooth components. The relation between copper future daily returns in LME and that in SHFE are different on different time scales. The fluctuations of the copper future daily returns in LME have large effect on that in SHFE in 32-day scale,but small effect in high frequency scales. It also has evidence that strong effects exist between LME and SHFE for monthly responses of the copper futures but not for daily responses.

Spillover of international crude oil prices on China's refined oil wholesale prices and price forecasting:Daily-frequency data of private enterprises and local refineries

Compared with retail prices of state-owned companies used in almost all existing studies,China’s refined oil wholesale prices of private enterprises and local refineries are more affected by the market and better reflect the real supply-demand situation.For the first time,this paper applies own-monitored dailyfrequency wholesale prices of China’s private enterprises and local refineries during 2013-2020 to derive spillover effects of international crude oil prices on China’s refined oil prices through the VAR-BEKKGARCH(vector autoregression-Baba,Engle,Kraft,and Kroner-generalized autoregressive conditional heteroscedasticity)model,and then tries to forecast wholesale prices through the PCA-BP(principal component analysis-back propagation)neural network model.Results show that international crude oil prices have significant mean spillover and volatility spillover effects on China’s refined oil wholesale prices.Changes in crude oil prices are the Granger cause of changes in refined oil wholesale prices.With the improvement of China’s oil-pricing mechanism in 2016,the volatility spillover from the international crude oil market to China’s refined oil market gradually increases,and the BRENT price variation has an increasing impact on the refined oil wholesale price variation.The PCA-BP model could serve as a candidate tool for forecasting China’s refined oil wholesale prices.

Empirical research on the international spillover effects of U.S. monetary policy and their impacts

Empirical research has shown that there were international spillover effects from the U.S. monetary policy to output level, net exports and price levels of each country, and the impact on prices in each country was of synchronous effect. The structural impulse response analysis showed that U.S. monetary policy could improve U.S. income and payment without damaging U.S. economic growth, but the shocks negatively affected the economic growth in the rest of the world. Hence, it's important to pay close attention to the moral risks of U.S. monetary policy to evade the global shocks caused by the "benefit-itself-at-the-expense-of-others" polices of the American government. Besides these findings, U.S. monetary policy shocks strongly affect China's trade surplus fluctuations. Based on this, we propose that the approaches of balancing China's current account could be explored efficiently from the perspective of monetary policy.

A spillover network analysis of the global crude oil market:Evidence from the post-financial crisis era

The frequent occurrence of geopolitical crises in the post-financial crisis era is driving the rethinking behind whether the global crude oil market is still a highly connected"great pool".Using the spillover network model suggested by Baruník and Krehlík(2018),and the daily data of 31 global crude oil markets from 2009 to 2019,this study examines the return and volatility spillover effects and their timevarying behavior in six crude oil market segments at different timescales.The findings indicate that heterogeneity exists in the co-movements between global crude oil markets in the post-financial crisis era.In the medium term,both return and volatility spillover effects are not significant,which makes the diversified portfolio strategy useful.Prices in the Europe and Central Asian regions take the lead in return spillovers.In contrast,Asia-Pacific regional prices contribute the most in terms of volatility spillovers.Long-term volatility spillovers increase sharply when confronted with oil-related events in the postfinancial crisis era.Therefore,policymakers should take effective measures to prevent any large-scale risk transmission in the long run.

Spatial emission reduction effects of China’s carbon emissions trading:quasi-natural experiments and policy spillovers

Insufficient assessment of emission reduction effects still exists in the carbon emission rights trading system,a major environmental regulation measure in China.Based on the data from the carbon trading pilot covering the years from 2007 to 2017,this study combined the synthetic control method with dynamic spatial Durbin model to comprehensively evaluate the spatial emission reduction effects of carbon trading policies.The results showed that:①The carbon trading policies promoted carbon emission reductions in the pilot regions,among which Tianjin and Hubei responded significantly,and also helped to suppress carbon emissions in the neighboring areas.②Long-term emission reduction effect from carbon emissions trading became gradually significant,while the indirect emission reduction effect was relatively weaker.③In term of reducing carbon emissions,the economic development channel played a key role,but it had a threat to the promotion of carbon emissions in the surrounding areas.Energy consumption was the main obstacle to the growth of carbon emissions.④In the long run,technological progress tended to become the key to the effective implementation of potential emission reduction effects of carbon trading policies.Based on the above findings,we suggest that the construction of a national carbon trading market should be promoted,the balanced development and orderly advancement of regional carbon trading markets should be paid attention to,the coordinated development of green economy as well as knowledge and technology exchange and cooperation among regions should be strengthened to form a low carbon development model among regions.

Volatility spillover effect between financial markets:evidence since the reform of the RMB exchange rate mechanism

The volatility spillover effect between the foreign exchange and stock markets has been a major issue in economic and financial studies.In this paper,GC-MSV model was used to study the spillover effect between the foreign exchange market and the stock market after the reform of the RMB exchange rate mechanism.The empirical results show that there is a negative correlation of dynamic price spillovers between the foreign exchange and stock markets.There are asymmetric volatility spillover effects between these two markets for both RMB stages—continued RMB appreciation or constant RMB shock(a significant reduction in appreciation).However,this has been reduced over time.In conclusion,The RMB exchange rate is a key variable that can affect the internal and external equilibrium of the national economy in an open economic environment,and the stock market is capable of quickly reflecting subtle changes in the real economy.In order to keep the stability of the financial markets and the healthy and rapid development of national economy,some suggestions were proposed.

Spatial Spillover and the Factors Influencing Public Service Supply in Sichuan Province, China

This article examines the spatial characteristics of public service supply and the factors influencing such supply in cities of Sichuan Province, China using spatial-autocorrelation and spatial econometric models with statistical data in 2012. The results demonstrate that expenditures on different types of public services present different spatial autocorrelation patterns. Although the spatial differences in basic public service expenditures are relatively small, a clear fan-shaped spillover to the east can be seen in Chengdu City. Chengdu also shows high clustering of advanced public service expenditures, being a typical core-periphery pattern. Post-earthquake reconstruction expenditures are clustered in the "5.12 Wenchuan earthquake" region and spill over toward cities to the east. The efficiency of public services in the mountainous areas in western Sichuan is low and exhibits a pattern of low-low spatial autocorrelation. The efficiency of public service supply is affected by economic, social, political and geographical factors. Based on the results of this analysis, we recommend a supply strategy that incorporates different types of public services and a specialized public service supply strategy for mountainous areas. Overall public service efficiency should be enhanced by focusing on narrowing the gap in farmers' income among regions and accelerating urbanization. Decision-makers should consider moresupportive policies with regard to providing basic public services in mountainous areas to ensure an equalized supply of basic public services. To enhance the efficiency of advanced public service supply, additional growth pole should be encouraged and incentivized; however, investments are required to drive the development of the peripheral regions through regional economic integration. Both software and hardware types of infrastructure are required to supply services efficiently during post-disaster reconstruction.