【作者】 黄毅；

【导师】 银凤翔； 黄晓峰； 何小波；

【作者基本信息】 北京化工大学 ， 化学工程（专业学位）， 2019， 硕士

【摘要】 具有燃烧热值高,无污染等优点的可持续二次能源——氢能,被认为是最有可能替代化石燃料的新能源。目前,电解水制氢技术因其原料来源极其丰富,产物无污染,效率高等优势被广泛关注,然而由于电解池两极的极化问题阻碍了其发展。因此,研制出廉价、高活性、高稳定性的氢气析出(HER)与氧气析出(OER)双功能催化剂至关重要。近年来,具有结构优势的金属有机骨架(MOFs)以及具有催化潜力的过渡金属Mo、Ni、Co被广泛研究。本文以ZIF-8为C源、N源,磷钼酸为Mo源,采用液相自组装法以及一步煅烧法合成了 MoxC/CC-M系列催化剂。讨论了 Mo加入量M与煅烧温度对HER活性的影响。当Mo加入量为12 mmol,煅烧温度为850℃时,MoxC/CC-12-850在1 M KOH中具有最优的HER活性。在10 mA/cm2电流密度处的过电位η10仅为161 mV,Tafel斜率为71 mV/dec。通过XRD与SEM表征发现,MoxC/CC-12-850是以β-Mo2C为主要活性组分的催化剂,形貌为带有些许絮状的微小纳米条,整体形貌呈珊瑚状。为了制备同时具有HER与OER催化活性的双功能催化剂,又以ZIF-8为C源、N源,硝酸镍为Ni源,制备了 NiM/CNT系列催化剂。着重讨论了 Ni加入量M与煅烧温度对催化剂HER与OER活性的影响。在1 M KOH中,当Ni加入量为12 mmol,煅烧温度为850℃时,Ni12/CNT-850具有最优的HER与OER催化活性。其HER过电位η10为328mV,Tafel斜率为 102 mV/dec,OER 过电位η10为523 mV,Tafel 斜率为 205 mV/dec。Ni12/CNT是以Ni为主要催化成分的碳纳米管材料。为进一步制备活性更优的催化剂,探究双金属元素的协同作用。以ZIF-67为Co源、C源、N源,磷钼酸为Mo源,制备了 CoxMoxCx/CC-M系列催化剂。重点讨论了 Mo加入量M与煅烧温度对HER与OER性能的影响。当Mo加入量为12 mmol,煅烧温度为750℃时,CoxMoxCx/CC-12-750 具有最优的 HER 与 OER 性能。在 1 M KOH 中,HER过电位η10仅为180 mV,Tafel斜率为114 mV/dec,OER过电位η10仅为 375 mV,Tafel 斜率为 60 mV/dec。CoxMoxCx/CC-12-750 是以 β-Mo2C与Mo3Co3C为主要活性组分的碳材料,整体呈珊瑚块状。β-Mo2C与Mo3Co3C的协同作用增强了催化剂HER与OER活性。更多还原

【Abstract】 Hydrogen energy,a sustainable secondary energy with high calorific value and no pollution,is considered to be the new energy that most likely toreplace fossil fuels.At present,electrolyzed water hydrogen production technology is widely concerned because of its abundant raw material sources,non-1olluting products,and high efficiency.However,the polarization problem of the two poles of the electrolytic cell hinders its development.Therefore,it is very important to develop a hydrogen evolution(HER)and oxygen evolution(OER)catalyst with low cost,high activity and high stability.In recent years,metal-organic frameworks(MOFs)with structural advantages and transition metals Mo,Ni and Co with catalytic potential have been extensively studied.In this paper,ZIF-8 is used as C source,N source and phosphomolybdic acid as Mo source.MoxC/CC-M series catalysts were synthesized by liquid phase self-assembly method and one-step calcination method.The effect of Mo addition amount M and calcination temperature on HER activity was discussed.When Mo was added in an amount of 12 mmol and the calcination temperature was 850℃,MoxC/CC-12-850 had the best HER activity in 1 M KOH.At 10 mA/cm2 current density,its overpotential is only 161 mV and the Tafel slope is 71 mV/dec.Characterization by XRD and SEM,MoxC/CC-12-850 is a catalyst with β-Mo2C as the main active component,and it is a tiny nano-strip with a little flocculent shape.The overall morphology is coral-like.In order to prepare a bifunctional catalyst with both HER and OER catalytic activity,using ZIF-8 as C source,N source and nickel nitrate as Ni source,NiM/CNT series catalysts were synthesized by liquid phase self-assembly method and one-step calcination method.The effect of Ni addition amount M and calcination temperature on the activity of HER and OER catalysts was discussed.In 1 M KOH,Ni12/CNT-850 has the best HER and OER catalytic activity when Ni is added at 12 mmol and calcination temperature is 850℃.The HER overpotential η10 is 328 mV,the Tafel slope is 102 mV/dec,the OER overpotential η10 is 523 mV,and the Tafel slope is 205 mV/dec.Ni12/CNT is a carbon nanotube material having Ni as a main catalytic component.To further prepare a better active catalyst and explore the synergistic effect of bimetallic elements.Using ZIF-67 as Co source,C source,N source and phosphomolybdic acid as Mo source.CoxMoxCx/CC-M series catalysts were synthesized by liquid phase self-assembly method and one-step calcination method.The effects of Mo addition amount M and calcination temperature on the performance of HER and OER were discussed.When Mo is added in an amount of 12 mmol and the calcination temperature is 750℃,CoxMoxCx/CC-12-750 has the best HER and OER properties.In 1 M KOH,the HER overpotential η10 is only 180 mV,the Tafel slope is 114 mV/dec,the OER overpotential η10 is only 375 mV,and the Tafel slope is 60 mV/dec.CoxMoxCx/CC-12-750 is a carbon material with β-Mo2C and Mo3Co3C as main active components,and the whole is coral-like.The synergistic effect of β-Mo2C and Mo3Co3C enhances the HER and OER activities of the catalyst.更多还原