Zinc-modified Pt/SAPO-11 catalysts were prepared by incipient wetness impregnation and assessed in the hydroisomerization of n-octane.Their physicochemical properties were investigated using powder X-ray diffraction,s...Zinc-modified Pt/SAPO-11 catalysts were prepared by incipient wetness impregnation and assessed in the hydroisomerization of n-octane.Their physicochemical properties were investigated using powder X-ray diffraction,scanning electron microscopy,nitrogen adsorption-desorption,pyridine-adsorbed infrared spectroscopy,temperature-programmed desorption of NH3,temperature-programmed reduction of hydrogen,temperature-programmed desorption of hydrogen,transmission electron microscopy,and X-ray photoelectron spectroscopy.The addition of zinc resulted in high dispersion of platinum.Zinc acted as a competitive adsorbent,changed the location of platinum.The catalyst with a zinc loading of 0.5%gave the highest selectivity to dimethylhexanes,but the conversion was lower than those achieved with the other catalysts.Dimethylhexanes have large molecular diameters,and therefore their diffusion may be difficult.This weakens the catalytic activity of the zinc-modified catalysts and lowers the n-octane conversion.展开更多
The development of highly efficient and costeffective oxygen evolution reaction(OER)electrocatalysts for renewable energy systems is vitally essential.Modulation of the electronic structure through heteroatom doping i...The development of highly efficient and costeffective oxygen evolution reaction(OER)electrocatalysts for renewable energy systems is vitally essential.Modulation of the electronic structure through heteroatom doping is considered as one of the most potential strategies to boost OER performances.Herein,a rational design of Mn-doped NiFe layered double hydroxide/reduced graphene oxide(Mn-NiFe LDH/rGO)is demonstrated by a facile hydrothermal approach,which exhibits outstanding OER activity and durability.Experimental results and density functional theory(DFT)calculations manifest that the introduction of Mn can reprogram the electronic structure of surface active sites and alter the intermediate adsorption energy,consequently reducing the potential limiting activation energy for OER.Specifically,the optimal Mn-NiFe LDH/rGO composite shows an enhanced OER performance with an ultralow overpotential of 240 mV@10 mA cm^(-2),Tafel slope of 40.0 mV dec^(-1) and excellent stability.Such superior OER activity is comparable to those of the recently reported state-of-the-art OER catalysts.This work presents an advanced strategy for designing electrocatalysts with high activity and low cost for energy conversion applications.展开更多
基金supported by the National Natural Science Foundation of China(21676300)~~
文摘Zinc-modified Pt/SAPO-11 catalysts were prepared by incipient wetness impregnation and assessed in the hydroisomerization of n-octane.Their physicochemical properties were investigated using powder X-ray diffraction,scanning electron microscopy,nitrogen adsorption-desorption,pyridine-adsorbed infrared spectroscopy,temperature-programmed desorption of NH3,temperature-programmed reduction of hydrogen,temperature-programmed desorption of hydrogen,transmission electron microscopy,and X-ray photoelectron spectroscopy.The addition of zinc resulted in high dispersion of platinum.Zinc acted as a competitive adsorbent,changed the location of platinum.The catalyst with a zinc loading of 0.5%gave the highest selectivity to dimethylhexanes,but the conversion was lower than those achieved with the other catalysts.Dimethylhexanes have large molecular diameters,and therefore their diffusion may be difficult.This weakens the catalytic activity of the zinc-modified catalysts and lowers the n-octane conversion.
基金the National Natural Science Foundation of China(51902003 and 21771003)Anhui Province Natural Science Foundation(2008085QB53)the Natural Science Research Project of Anhui Province Education Department(KJ2019A0581)。
文摘The development of highly efficient and costeffective oxygen evolution reaction(OER)electrocatalysts for renewable energy systems is vitally essential.Modulation of the electronic structure through heteroatom doping is considered as one of the most potential strategies to boost OER performances.Herein,a rational design of Mn-doped NiFe layered double hydroxide/reduced graphene oxide(Mn-NiFe LDH/rGO)is demonstrated by a facile hydrothermal approach,which exhibits outstanding OER activity and durability.Experimental results and density functional theory(DFT)calculations manifest that the introduction of Mn can reprogram the electronic structure of surface active sites and alter the intermediate adsorption energy,consequently reducing the potential limiting activation energy for OER.Specifically,the optimal Mn-NiFe LDH/rGO composite shows an enhanced OER performance with an ultralow overpotential of 240 mV@10 mA cm^(-2),Tafel slope of 40.0 mV dec^(-1) and excellent stability.Such superior OER activity is comparable to those of the recently reported state-of-the-art OER catalysts.This work presents an advanced strategy for designing electrocatalysts with high activity and low cost for energy conversion applications.
