Efficient,stable,and noble‐metal‐free electrocatalysts for both the oxygen evolution reaction and the hydrogen evolution reaction are highly imperative for the realization of low‐cost commercial water‐splitting el...Efficient,stable,and noble‐metal‐free electrocatalysts for both the oxygen evolution reaction and the hydrogen evolution reaction are highly imperative for the realization of low‐cost commercial water‐splitting electrolyzers.Herein,a cost‐effective and ecofriendly strategy is reported to fabricate coral‐like FeNi(OH)x/Ni as a bifunctional electrocatalyst for overall water splitting in alkaline media.With the assistance of mild corrosion of Ni by Fe(NO3)3,in situ generated FeNi(OH)x nanosheets are intimately attached on metallic coral‐like Ni.Integration of these nanosheets with the electrodeposited coral‐like Ni skeleton and the supermacroporous Ni foam substrate forms a binder‐free hierarchical electrode,which is beneficial for exposing catalytic active sites,accelerating mass transport,and facilitating the release of gaseous species.In 1.0 mol L^-1 KOH solution,a symmetric electrolyzer constructed with FeNi(OH)x/Ni as both the anode and the cathode exhibits an excellent activity with an applied potential difference of 1.52 V at 10 mA cm^-2,which is superior to that of an asymmetric electrolyzer constructed with the state‐of‐the‐art RuO2‐PtC couple(applied potential difference of 1.55 V at 10 mA cm^-2).This work contributes a facile and reliable strategy for manufacturing affordable,practical,and promising water‐splitting devices.展开更多
Direct N2O decomposition has been investigated over bare NiO and a series of its alkali-promoted catalysts. These catalysts were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy （XPS） and fiel...Direct N2O decomposition has been investigated over bare NiO and a series of its alkali-promoted catalysts. These catalysts were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscopy. XPS analysis revealed that surface nickel is present in three forms： metal particles, NiO and Ni（OH）2. It is suggested that nickel（0） valent atoms are essential for the interaction with N2O molecules at the catalyst surfaces. Bare NiO exhibited a very low N2O decomposition reactivity. However, the alkali-containing catalysts exhibited a marked activity enhancement.展开更多
＂Decoupling＂ refers to the divergence of business cycles among different countries, while ＂re-coupling＂ corresponds to the convergence or the synchronization of business cycles among different countries. The decou...＂Decoupling＂ refers to the divergence of business cycles among different countries, while ＂re-coupling＂ corresponds to the convergence or the synchronization of business cycles among different countries. The decoupling debate is popular in the field of economics, especially after global financial crisis. As trade integration increased among Asian countries, business cycle synchronization among these countries was expected to increase through trade transmission. The aim of this study is to discover whether there has been decoupling or convergence of business cycles through various trade channels. However, theoretically, increased trade can lead to business cycle synchronization either rising or falling. Inter-industry trade resulting in higher specification will induce less synchronized business cycles, while intra-industry trade could lead to increased business cycle synchronization. Thus, it is important to distinguish between intra- and inter-industry trade flows. Both correlation and dynamic factor models are utilized to study the evolution of global business cycle linkages. Results indicate that the world factor has become less important in explaining macroeconomic fluctuations from sub-period 1961-1984 to sub-period 1985-2007, while regional factors do not play an important role in explaining aggregate volatility, with the expectation of consumption. Overall, the explanatory power of country factors increases. Domestic consumption and domestic investment variances are more driven by country and idiosyncratic factors than by the world factor, contrary to the output growth fluctuations. Regional factors and country factors also play a more prominent role in explaining gross import fluctuations than in explaining gross exports. Results cast doubt on the strong forms of both the decoupling and the re-coupling hypothesis.展开更多
This paper presents a straightforward model studying the performance of a solid oxide electrolysis cell at less computational effort while is still comprehensive accounting for details of all physics involved. The mod...This paper presents a straightforward model studying the performance of a solid oxide electrolysis cell at less computational effort while is still comprehensive accounting for details of all physics involved. The model is one dimensional and can be used to optimize SOECs that have composite electrodes. It includes an average mass transfer analysis used to simulate concentration polarization, activation polarization, as well as ohmic loss. The electrochemical reaction that occurs within the electrode functional layers has been accounted for in the calculation of the concentration polarization. This is believed to give a more realistic view of the mass transfer that occurs in SOECs with composite electrodes via a simple and straightforward one dimensional model. Experimental work with SOECs also has been done and some results are reported. The simulation results are compared with experimental data and the agreement is satisfactory. The model can be conveniently used for optimization of the SOEC electrodes and operational conditions.展开更多
文摘Efficient,stable,and noble‐metal‐free electrocatalysts for both the oxygen evolution reaction and the hydrogen evolution reaction are highly imperative for the realization of low‐cost commercial water‐splitting electrolyzers.Herein,a cost‐effective and ecofriendly strategy is reported to fabricate coral‐like FeNi(OH)x/Ni as a bifunctional electrocatalyst for overall water splitting in alkaline media.With the assistance of mild corrosion of Ni by Fe(NO3)3,in situ generated FeNi(OH)x nanosheets are intimately attached on metallic coral‐like Ni.Integration of these nanosheets with the electrodeposited coral‐like Ni skeleton and the supermacroporous Ni foam substrate forms a binder‐free hierarchical electrode,which is beneficial for exposing catalytic active sites,accelerating mass transport,and facilitating the release of gaseous species.In 1.0 mol L^-1 KOH solution,a symmetric electrolyzer constructed with FeNi(OH)x/Ni as both the anode and the cathode exhibits an excellent activity with an applied potential difference of 1.52 V at 10 mA cm^-2,which is superior to that of an asymmetric electrolyzer constructed with the state‐of‐the‐art RuO2‐PtC couple(applied potential difference of 1.55 V at 10 mA cm^-2).This work contributes a facile and reliable strategy for manufacturing affordable,practical,and promising water‐splitting devices.
文摘Direct N2O decomposition has been investigated over bare NiO and a series of its alkali-promoted catalysts. These catalysts were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscopy. XPS analysis revealed that surface nickel is present in three forms： metal particles, NiO and Ni（OH）2. It is suggested that nickel（0） valent atoms are essential for the interaction with N2O molecules at the catalyst surfaces. Bare NiO exhibited a very low N2O decomposition reactivity. However, the alkali-containing catalysts exhibited a marked activity enhancement.
文摘＂Decoupling＂ refers to the divergence of business cycles among different countries, while ＂re-coupling＂ corresponds to the convergence or the synchronization of business cycles among different countries. The decoupling debate is popular in the field of economics, especially after global financial crisis. As trade integration increased among Asian countries, business cycle synchronization among these countries was expected to increase through trade transmission. The aim of this study is to discover whether there has been decoupling or convergence of business cycles through various trade channels. However, theoretically, increased trade can lead to business cycle synchronization either rising or falling. Inter-industry trade resulting in higher specification will induce less synchronized business cycles, while intra-industry trade could lead to increased business cycle synchronization. Thus, it is important to distinguish between intra- and inter-industry trade flows. Both correlation and dynamic factor models are utilized to study the evolution of global business cycle linkages. Results indicate that the world factor has become less important in explaining macroeconomic fluctuations from sub-period 1961-1984 to sub-period 1985-2007, while regional factors do not play an important role in explaining aggregate volatility, with the expectation of consumption. Overall, the explanatory power of country factors increases. Domestic consumption and domestic investment variances are more driven by country and idiosyncratic factors than by the world factor, contrary to the output growth fluctuations. Regional factors and country factors also play a more prominent role in explaining gross import fluctuations than in explaining gross exports. Results cast doubt on the strong forms of both the decoupling and the re-coupling hypothesis.
文摘This paper presents a straightforward model studying the performance of a solid oxide electrolysis cell at less computational effort while is still comprehensive accounting for details of all physics involved. The model is one dimensional and can be used to optimize SOECs that have composite electrodes. It includes an average mass transfer analysis used to simulate concentration polarization, activation polarization, as well as ohmic loss. The electrochemical reaction that occurs within the electrode functional layers has been accounted for in the calculation of the concentration polarization. This is believed to give a more realistic view of the mass transfer that occurs in SOECs with composite electrodes via a simple and straightforward one dimensional model. Experimental work with SOECs also has been done and some results are reported. The simulation results are compared with experimental data and the agreement is satisfactory. The model can be conveniently used for optimization of the SOEC electrodes and operational conditions.
