The Construction,regulation Of Pt-based Catalysts Based On 3D Mesoporous Carbon And Its Application In The Methanol Electrooxidation Reaction

The continuous deterioration of ecological environment and the gradually exhausted non-renewable energy resources have compelled human beings to develop advanced energy conversion and storage devices,which are environmental friendly and sustainable,direct methanol fuel cells（DMFCs）have been widely concerned for its high energy transition efficiency,high power density,environmental friendliness and abundant fuel sources.Its large-scale commercial applications,however,have been severely hampered for the high cost,low utilization and poor stability of the anode Pt-based catalysts.In view of the huge potential of nanoporous carbons（NPCs）based supports in reducing cost and improving catalytic activity as well as stability,in this thesis,based on the current development status of NPCs-based catalysts,the following works were conducted to manipulate the NPCs’pore size composition and chemical composition to ameliorate the methanol oxidation reaction（MOR）performance of NPCs-based catalysts.Firstly,to reduce the content of deleterious micropores and optimize the synthetic method,3D nanoarchitectures（Co@NCNT-NG）have been fabricated via a facile and eco-friendly annealing approach,utilizing in-suit formed nitrogen-doped carbon nanotubes（NCNTs）,which are catalyzed by Co,as the spacers of in-suit formed nitrogen-doped graphene-like carbon nanosheets（NGs）.Characterizations manifest that the NCNTs make for improving graphitic degree and promoting the formation of opened macropores;while NGs contribute to increasing the specific surface area and the level of N-doping,what’s more,unlike conventional NPCs,at 900℃and the optimal content ratio between NCNTs and NGs,the Co@NCNT-NG mainly consists of 3D macropores and oversized mesoporous.Benefiting from the improved electron transfer rate,the co-catalytic effect of N and the affluent mass transfer caused by the oversized mesoporous,the Pt/Co@NCNT-NG exhibits excellent MOR activity and stability.Secondly,via a facile and eco-friendly mechanical lapping,synchronous phosphorization pyrolysis and Na BH₄ reduction procedure,we have constructed a novel nanoarchitecture,which confines transition metal phosphide（TMPs）within mesoporous carbon as the support of Pt nanoparticles（Pt NPs）for the first time（Pt/Ni Co P_x@NCNT-NG）.Unlike the naked TMPs/carbon hybrids supports,the TMPs are tightly encapsulated by graphene shells,which effectively blocks its direct contact with air and electrolyte,such feature is beneficial to maintain the co-catalytic effect of TMPs;The large specific surface area and mesoporous structure of Ni Co P_x@NCNT-NG not only promote the uniform dispersion of Pt NPs,but ensure the efficient mass transfer in the catalytic process,in spite of without immediate contact,the electron interactions between Ni Co P_x and Pt proceed as well.On account of the synergistic effect of TMPs,Pt NPs and mesoporous carbons,the utilization and CO-tolerance of Pt is enhanced,as a result,the Pt/Ni Co P_x@NCNT-NG reveals better catalytic activity and stability for MOR.In addition,due to the protection of graphitized carbon,the activity of Pt/Ni Co P_x@NCNT-NG has almost no decay after air exposure treatment for 60 days.