NaBH_(4) was widely regarded as a low-cost hydrogen storage material due to its high-mass hydrogen capacity of approximately 10.8%(mass)and high volumetric hydrogen capacity of around 115 g·L^(–1).However,it exh...NaBH_(4) was widely regarded as a low-cost hydrogen storage material due to its high-mass hydrogen capacity of approximately 10.8%(mass)and high volumetric hydrogen capacity of around 115 g·L^(–1).However,it exhibits strong stability and requires temperatures above 500℃ for hydrogen release in practical applications.In this study,two polyhydric alcohols,xylitol and erythritol(XE),were prepared as a binary eutectic sugar alcohol through a grinding-melting method.This binary eutectic sugar alcohol was used as a proton-hydrogen carrier to destabilize NaBH_(4).The 19NaBH_(4)-16XE composite material prepared by ball milling could start releasing hydrogen at 57.5℃,and the total hydrogen release can reach over 88.8%(4.45%(mass))of the theoretical capacity.When the 19NaBH_(4)-16XE composite was pressed into solid blocks,the volumetric hydrogen capacity of the block-shaped composite could reach 67.2 g·L^(–1).By controlling the temperature,the hydrogen desorption capacity of the NaBH_(4)-XE composite material was controllable,which has great potential for achieving solid-state hydrogen production from NaBH_(4).展开更多
Sodium borohydride(NaBH_(4)) is considered as the most potential hydrogen storage material for portable proton exchange membrane fuel cells(PEMFC)because of its high theoretical hydrogen capacity.However,the slow and ...Sodium borohydride(NaBH_(4)) is considered as the most potential hydrogen storage material for portable proton exchange membrane fuel cells(PEMFC)because of its high theoretical hydrogen capacity.However,the slow and poor kinetic stability of hydrogen generation from NaBH_(4) hydrolysis limits its application.There are two main factors influencing the kinetics stability of hydrogen generation from NaBH_(4).One factor is that the alkaline byproducts(NaBO_(2)) of the hydrolysis reaction can increase the pH of the solution,thus inhibiting the reaction process.It mainly happens in the NaBH_(4) solution hydrolysis system.Another factor is that the monotonous increase in reaction temperature leads to uncontrollable and unpredictable hydrolysis rates in the solid NaBH_(4) hydrolysis system.This is due to the excess heat generated from this exothermic reaction in the initial reaction of NaBH_(4) hydrolysis.In this perspective,we summarize the latest research progress in hydrogen generation from NaBH_(4) and emphasize the design principles of catalysts for hydrogen generation from NaBH_(4) solution and solid state NaBH_(4).The importance of carbon as catalyst support material for NaBH_(4) hydrolysis is also highlighted.展开更多
基金support from the National Natural Science Foundation of China(52201255)the Natural Science Foundation of Jiangsu Province(BK20210884)the Innovation,and Entrepreneurship Program of Jiangsu Province(JSSCBS20211007).
文摘NaBH_(4) was widely regarded as a low-cost hydrogen storage material due to its high-mass hydrogen capacity of approximately 10.8%(mass)and high volumetric hydrogen capacity of around 115 g·L^(–1).However,it exhibits strong stability and requires temperatures above 500℃ for hydrogen release in practical applications.In this study,two polyhydric alcohols,xylitol and erythritol(XE),were prepared as a binary eutectic sugar alcohol through a grinding-melting method.This binary eutectic sugar alcohol was used as a proton-hydrogen carrier to destabilize NaBH_(4).The 19NaBH_(4)-16XE composite material prepared by ball milling could start releasing hydrogen at 57.5℃,and the total hydrogen release can reach over 88.8%(4.45%(mass))of the theoretical capacity.When the 19NaBH_(4)-16XE composite was pressed into solid blocks,the volumetric hydrogen capacity of the block-shaped composite could reach 67.2 g·L^(–1).By controlling the temperature,the hydrogen desorption capacity of the NaBH_(4)-XE composite material was controllable,which has great potential for achieving solid-state hydrogen production from NaBH_(4).
基金supported by MOST of China(No.2021YFB4000603)NSFC(No.22179002 and 51971004).
文摘Sodium borohydride(NaBH_(4)) is considered as the most potential hydrogen storage material for portable proton exchange membrane fuel cells(PEMFC)because of its high theoretical hydrogen capacity.However,the slow and poor kinetic stability of hydrogen generation from NaBH_(4) hydrolysis limits its application.There are two main factors influencing the kinetics stability of hydrogen generation from NaBH_(4).One factor is that the alkaline byproducts(NaBO_(2)) of the hydrolysis reaction can increase the pH of the solution,thus inhibiting the reaction process.It mainly happens in the NaBH_(4) solution hydrolysis system.Another factor is that the monotonous increase in reaction temperature leads to uncontrollable and unpredictable hydrolysis rates in the solid NaBH_(4) hydrolysis system.This is due to the excess heat generated from this exothermic reaction in the initial reaction of NaBH_(4) hydrolysis.In this perspective,we summarize the latest research progress in hydrogen generation from NaBH_(4) and emphasize the design principles of catalysts for hydrogen generation from NaBH_(4) solution and solid state NaBH_(4).The importance of carbon as catalyst support material for NaBH_(4) hydrolysis is also highlighted.
