The Application Of Pt@CA For Aluminum Air Battery

Platinum-carbon catalyst（Pt/C）is one kind of supported catalyst that supports platinum on carbon,and Pt/C is one of the most widely used precious metal catalysts.Due to the high catalytic activity of Pt/C for oxygen reduction reaction（ORR）,carbon-supported nano-platinum catalyst is widely appilied in aluminum Air battery.However,as the catalyst of the ORR,before the practical application and commercialization,there are still many problems and challenges of Pt/C to be solved,incliding poor durability,low efficiency and high price.The support of the nano-platinum is a key factor affecting the catalytic performance of Pt catalysts.Carbon aerogel（CA）microsphere is recognized as the ideal materials of support due to its religious electrical conductivity,high specific surface area and rich porous structure.More notably,CA microspheres can be prepared by reverse microemulsion and ambient pressure drying,paving a way to the commercialization of support materials.Whereas,the pore size of the traditional resorcinol-formaldehyde carbon aerogel（CRF）microspheres is too small（1-10 nm）to support Pt catalysts.In this study,we develop a novel phloroglucinol-resorcinol-formaldehyde carbon aerogel（CPRF）microspheres via designing the mesopore structure of CA microspheres,utilizing phloroglucinol,resorcinol,formaldehyde as raw materials,and adding degradable polymer polyethylene glycol 200 in the precursor solution.These CPRF microspheres have applicable pore distribution,high medium porosity and large specific surface area.Finally,Pt/CA catalyst was prepared via ethylene glycol process,and the catalytic performance of Pt/CA for ORR was test.The specific content and wxperimental conclusions are as follows:1.The effect of mesopore structure CPRF microspheres was investigated by controlling the ratio of phloroglucinol to resorcinol.The result of this study shows that under appropriate preparation conditions and activation processes,the ratio of resorcinol to resorcinol has a significant effect on the pore size and distribution of carbon aerogel microspheres.Adjusting the appropriate ratio can obtAln effective mesopores that are favorable for nano-Pt catalyst support.The mesopore specific surface area of ACPRF-7 is as high as 374.8 m²·g^-1.Furthermore,ACPRF-7 possesses suitable mesopore pore size（15-30nm）,and there is no excess micropores of it.The electrochemically active surface area of Pt/ACPRF-7 prepared by the ethylene glycol process is as high as 176.7 m²·g^-1.As the catalyst for ORR,the initial mass activity of Pt/ACPRF-7 is as high as 0.21A·mg^-1.After accelerated durability tests,the mass activity was still up to 0.15 A·mg^-1.2.Template method for the preparation of CPRF microspheres with high and medium porosity.The carbon activation process mentioned earlier is complicated and expensive,more importantly,many microporous structures are produced along with the activation process,which is not conducive to support Pt catalyst.And a lat of impurity iron ions will be introduced during the activation process of industrial-grade production.In this paper,the template method is used to avoid the activation process and to obtain high-medium porosity,large specific surface area CPRF microspheres that are favorable for supporting Pt catalyst.By research,CPRF-0.75 prepared with the appropriate content of PEG-200 is the most ideal support for Pt catalyst.CPRF-0.75 has suitable mesopore diameter（15-35nm）and high mesopore specific surface area(295.0 m²·g^-1).Pt/CPRF-0.75 prepared by the ethylene glycol process showed a high electrochemically active surface area(155 m²·g^-1).As the catalyst of the ORR,the initial mass activity of Pt/CPRF-0.75 is as high as 0.2 A·mg^-1.After the accelerated durability test,the mass activity is still as high as 0.11 A·mg^-1.3.In order to investigate the commercial application value of the preparation method of Pt/CA,the prepared Pt/CA catalysts are compared with the commercially avAllable Pt/ C catalyst.Finding that the ORR catalytic performance of Pt/CA catalysts is much higher than that of other commercial Pt/C catalysts,and the cost of Pt/CA is lower.Pt/CA catalysts have high commercial development potential.4.In order to furtherly explore the commercial development potential of this method,a small-scale test verification was carried out on an industrialized small-scale test line.The results show that the performance of the product prepared by the 100 upgraded test line is basically the same as that of the laboratory sample.