负载型Pd基催化剂是最有效的甲酸分解(FAD)制氢催化剂之一,其中氮化碳载体的N含量较高,但是通常一步热解法制备的氮化碳为块状,难以有效分散表面金属纳米粒子(NPs)。本文通过将尿素前驱体在溶剂化作用后热解得到功能化氮化碳,以此为载体...负载型Pd基催化剂是最有效的甲酸分解(FAD)制氢催化剂之一,其中氮化碳载体的N含量较高,但是通常一步热解法制备的氮化碳为块状,难以有效分散表面金属纳米粒子(NPs)。本文通过将尿素前驱体在溶剂化作用后热解得到功能化氮化碳,以此为载体,利用阴离子交换和硼氢化钠直接还原法制备了功能化氮化碳负载的Pd基催化剂(Pd/C 3 N 4-F)。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)对材料结构进行表征,并通过气体质量流量计测试了催化剂的性能。Pd/C 3 N 4-F具有优异的催化FAD制氢性能,30℃下的初始TOF(总转换频率)值和质量比活性分别为1824 h-1和17.14 mol H 2/(g Pd·h)。对产物的气相色谱分析结果也表明没有副产物CO生成,表明催化剂具有优异的选择性。并且随着温度的升高(30~40℃),催化剂性能逐渐提高。展开更多
The material innovation is prerequisite to accelerating sluggish oxygen evolution reaction(OER)kinetics,thus promoting the realization of hydrogen energy community.Herein,we develop an oxygen-vacancy-rich TiO_(2)suppo...The material innovation is prerequisite to accelerating sluggish oxygen evolution reaction(OER)kinetics,thus promoting the realization of hydrogen energy community.Herein,we develop an oxygen-vacancy-rich TiO_(2)supported RuO_(2)catalyst(RuO_(2)@r-TiO_(2))towards improved OER activity and stability.The oxygen vacancy on TiO_(2)not only supplies electrons to produce lower valence Ru,but also provides sufficient anchoring site for the deposition of RuO_(2)nanocrystal.Beyond that,it can generate strong electronic interaction between TiO_(2)and supported RuO_(2),and thereby tailors the intermediates’adsorption energy on the RuO_(2)surface.As a result,the derived RuO_(2)@r-TiO_(2)catalyst exhibits superior OER activity and stability with the overpotential of 211 mV at a current density of 10 mA cm^(−2)and negligible activity degradation after 6 h operation,outperforming the non-oxygen-vacancy counterpart(223.3 mV,12.75%activity loss)and RuO_(2)catalyst(234.6 mV,42.86%activity loss).展开更多
A series of proton exchange membranes based on sulfonated polyarylene ether ketones（SPAEKs） was used to study the effect of sulfonation degree on proton conductivity, methanol permeation and performance of direct me...A series of proton exchange membranes based on sulfonated polyarylene ether ketones（SPAEKs） was used to study the effect of sulfonation degree on proton conductivity, methanol permeation and performance of direct methanol fuel cells（DMFCs）. Dependences of physical characteristics of the membranes, i. e., proton conductivity, water uptake, swelling ratio, methanol permeability and ion exchange capacity（IEC） were systematically studied. Both methanol permeability and proton conductivity of the SPAEK membrane grow rapidly as the increase in sulfonation degree since methanol molecules and protons share the same transfer channel. However, the methanol permeability plays more important role comparing to proton conductivity. As a result, the SPAEK membrane with a medium sulfonation degree（60%） was found to yield the best performance in a DMFC due to the acquirement of balanced conductivity and methanol permeability.展开更多
文摘负载型Pd基催化剂是最有效的甲酸分解(FAD)制氢催化剂之一,其中氮化碳载体的N含量较高,但是通常一步热解法制备的氮化碳为块状,难以有效分散表面金属纳米粒子(NPs)。本文通过将尿素前驱体在溶剂化作用后热解得到功能化氮化碳,以此为载体,利用阴离子交换和硼氢化钠直接还原法制备了功能化氮化碳负载的Pd基催化剂(Pd/C 3 N 4-F)。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)对材料结构进行表征,并通过气体质量流量计测试了催化剂的性能。Pd/C 3 N 4-F具有优异的催化FAD制氢性能,30℃下的初始TOF(总转换频率)值和质量比活性分别为1824 h-1和17.14 mol H 2/(g Pd·h)。对产物的气相色谱分析结果也表明没有副产物CO生成,表明催化剂具有优异的选择性。并且随着温度的升高(30~40℃),催化剂性能逐渐提高。
基金supported by the National Key R&D Program of China(Grant No. 2020YFB1506802)the National Natural Science Foundation of China (Grant Nos. 21633008, U1601211, and 21733004)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDA21090400)Jilin Province Science and Technology Development Program (Grant Nos. 20190201300JC, 20170520150JH, and20200201001JC)
文摘The material innovation is prerequisite to accelerating sluggish oxygen evolution reaction(OER)kinetics,thus promoting the realization of hydrogen energy community.Herein,we develop an oxygen-vacancy-rich TiO_(2)supported RuO_(2)catalyst(RuO_(2)@r-TiO_(2))towards improved OER activity and stability.The oxygen vacancy on TiO_(2)not only supplies electrons to produce lower valence Ru,but also provides sufficient anchoring site for the deposition of RuO_(2)nanocrystal.Beyond that,it can generate strong electronic interaction between TiO_(2)and supported RuO_(2),and thereby tailors the intermediates’adsorption energy on the RuO_(2)surface.As a result,the derived RuO_(2)@r-TiO_(2)catalyst exhibits superior OER activity and stability with the overpotential of 211 mV at a current density of 10 mA cm^(−2)and negligible activity degradation after 6 h operation,outperforming the non-oxygen-vacancy counterpart(223.3 mV,12.75%activity loss)and RuO_(2)catalyst(234.6 mV,42.86%activity loss).
基金Supported by the National Natural Science Foundation of China（No.21074044）, the National Basic Research Program of China（Nos.2011CB935700, 2012CB215500） and the National High Technology Research and Development Program of China （No .2012AA053401）.
文摘A series of proton exchange membranes based on sulfonated polyarylene ether ketones（SPAEKs） was used to study the effect of sulfonation degree on proton conductivity, methanol permeation and performance of direct methanol fuel cells（DMFCs）. Dependences of physical characteristics of the membranes, i. e., proton conductivity, water uptake, swelling ratio, methanol permeability and ion exchange capacity（IEC） were systematically studied. Both methanol permeability and proton conductivity of the SPAEK membrane grow rapidly as the increase in sulfonation degree since methanol molecules and protons share the same transfer channel. However, the methanol permeability plays more important role comparing to proton conductivity. As a result, the SPAEK membrane with a medium sulfonation degree（60%） was found to yield the best performance in a DMFC due to the acquirement of balanced conductivity and methanol permeability.
