Transition metal phosphides are a class of promising electrocatalysts for hydrogen evolution reaction(HER) to replace noble metals.In this work,we for the first time synthesize carbon supported CoP nanoparticles with ...Transition metal phosphides are a class of promising electrocatalysts for hydrogen evolution reaction(HER) to replace noble metals.In this work,we for the first time synthesize carbon supported CoP nanoparticles with the average particle sizes from 3.3 to 9.2 nm,via a solvothermal process followed by low-temperature topological phosphorization,and the size-dependent HER activity of the CoP is investigated by virtue of TEM,XRD,XPS and the electrochemical techniques.It is discovered that the 9.2nm-CoP particles possess high intrinsic HER catalytic activity as compared to the 3.3nm-CoP,although the smaller one displays a high mass activity due to the large surface area.Detailed studies manifest that the small CoP particles suffer from serious oxidation once exposing to air.In contrast,most cobalt remains in the quasi-metallic state in the relatively large CoP particles,which is beneficial for the desorption of Hads,the rate determining step of the HER process over CoP surface.In addition,the low charge transfer resistance across the liquid/solid interfaces also contributes to the excellent HER activity of the relatively large CoP particles.展开更多
采用共沉淀法制备了水溶性聚合物修饰的苯选择加氢制环己烯Ru-Zn催化剂,并用X射线衍射、透射电镜、X射线能量色散谱、X射线光电子能谱和氮气物理吸附等对加氢后催化剂进行了表征.结果表明,水溶性聚合物的种类和聚乙二醇-20000(PEG-20000...采用共沉淀法制备了水溶性聚合物修饰的苯选择加氢制环己烯Ru-Zn催化剂,并用X射线衍射、透射电镜、X射线能量色散谱、X射线光电子能谱和氮气物理吸附等对加氢后催化剂进行了表征.结果表明,水溶性聚合物的种类和聚乙二醇-20000(PEG-20000)的用量对Ru-Zn催化剂微晶尺寸有显著影响.在Zn SO4存在下,随着Ru-Zn催化剂Ru微晶尺寸增加,苯转化率降低,环己烯最高收率则呈火山型变化趋势.用0.4 g PEG-20000修饰的Ru-Zn催化剂[m(PEG-20000)∶m(Ru)=0.2]Ru的微晶尺寸为4.8 nm,环己烯最高收率为62.2%.Ru微晶尺寸影响催化剂表面的Zn/Ru原子比,进而影响Ru-Zn催化剂性能.展开更多
基金financially supported by the National Natural Science Foundation of China(21576258,21776146)the Key Research and Development Project of Shandong Province(2018GGX102036)Taishan Scholar Program of Shandong Province(ts201712046)。
文摘Transition metal phosphides are a class of promising electrocatalysts for hydrogen evolution reaction(HER) to replace noble metals.In this work,we for the first time synthesize carbon supported CoP nanoparticles with the average particle sizes from 3.3 to 9.2 nm,via a solvothermal process followed by low-temperature topological phosphorization,and the size-dependent HER activity of the CoP is investigated by virtue of TEM,XRD,XPS and the electrochemical techniques.It is discovered that the 9.2nm-CoP particles possess high intrinsic HER catalytic activity as compared to the 3.3nm-CoP,although the smaller one displays a high mass activity due to the large surface area.Detailed studies manifest that the small CoP particles suffer from serious oxidation once exposing to air.In contrast,most cobalt remains in the quasi-metallic state in the relatively large CoP particles,which is beneficial for the desorption of Hads,the rate determining step of the HER process over CoP surface.In addition,the low charge transfer resistance across the liquid/solid interfaces also contributes to the excellent HER activity of the relatively large CoP particles.
文摘采用共沉淀法制备了水溶性聚合物修饰的苯选择加氢制环己烯Ru-Zn催化剂,并用X射线衍射、透射电镜、X射线能量色散谱、X射线光电子能谱和氮气物理吸附等对加氢后催化剂进行了表征.结果表明,水溶性聚合物的种类和聚乙二醇-20000(PEG-20000)的用量对Ru-Zn催化剂微晶尺寸有显著影响.在Zn SO4存在下,随着Ru-Zn催化剂Ru微晶尺寸增加,苯转化率降低,环己烯最高收率则呈火山型变化趋势.用0.4 g PEG-20000修饰的Ru-Zn催化剂[m(PEG-20000)∶m(Ru)=0.2]Ru的微晶尺寸为4.8 nm,环己烯最高收率为62.2%.Ru微晶尺寸影响催化剂表面的Zn/Ru原子比,进而影响Ru-Zn催化剂性能.
