Development of Graphene-Based Anode Materials for Use in Boron-Derivative Fuel Cells and Investigation of Their Effects on Fuel Cell Performance

Project no. 25278 · Status: Kapanmış (Yayın bekleniyor) · 2023

Summary

<p> In&nbsp;this&nbsp;project,&nbsp;different&nbsp;graphene-based&nbsp;support&nbsp;materials&nbsp;were&nbsp;developed&nbsp;for&nbsp;use&nbsp;as&nbsp;anode&nbsp;electrocatalysts&nbsp;in&nbsp;direct&nbsp;borohydride&nbsp;and&nbsp;direct&nbsp;ammonium&nbsp;borane&nbsp;fuel&nbsp;cells.&nbsp;In&nbsp;the&nbsp;first&nbsp;stage,&nbsp;graphene&nbsp;oxide&nbsp;(GO)&nbsp;was&nbsp;synthesized,&nbsp;followed&nbsp;by&nbsp;the&nbsp;preparation&nbsp;of&nbsp;reduced&nbsp;graphene&nbsp;(GR),&nbsp;nitrogen-doped&nbsp;graphene&nbsp;(N-GR),&nbsp;and&nbsp;fluorine-doped&nbsp;graphene&nbsp;(F-GR).&nbsp;Au–Ni,&nbsp;Au–Zn,&nbsp;and&nbsp;Au–Co&nbsp;bimetallic&nbsp;catalysts&nbsp;were&nbsp;subsequently&nbsp;electrodeposited&nbsp;onto&nbsp;the&nbsp;prepared&nbsp;graphene&nbsp;supports&nbsp;to&nbsp;fabricate&nbsp;different&nbsp;anode&nbsp;electrodes.&nbsp;The&nbsp;structural,&nbsp;morphological,&nbsp;and&nbsp;surface&nbsp;properties&nbsp;of&nbsp;the&nbsp;synthesized&nbsp;electrodes&nbsp;were&nbsp;characterized&nbsp;using&nbsp;scanning&nbsp;electron&nbsp;microscopy&nbsp;(SEM),&nbsp;energy-dispersive&nbsp;X-ray&nbsp;spectroscopy&nbsp;(EDS),&nbsp;X-ray&nbsp;diffraction&nbsp;(XRD),&nbsp;and&nbsp;X-ray&nbsp;photoelectron&nbsp;spectroscopy&nbsp;(XPS).&nbsp;Their&nbsp;electrochemical&nbsp;performances&nbsp;were&nbsp;evaluated&nbsp;by&nbsp;cyclic&nbsp;voltammetry,&nbsp;chronoamperometry,&nbsp;and&nbsp;scan&nbsp;rate&nbsp;studies,&nbsp;while&nbsp;the&nbsp;oxidation&nbsp;behaviors&nbsp;of&nbsp;sodium&nbsp;borohydride&nbsp;and&nbsp;ammonium&nbsp;borane&nbsp;in&nbsp;alkaline&nbsp;media&nbsp;were&nbsp;investigated&nbsp;in&nbsp;detail.&nbsp;Furthermore,&nbsp;the&nbsp;performances&nbsp;of&nbsp;the&nbsp;developed&nbsp;anode&nbsp;electrodes&nbsp;in&nbsp;direct&nbsp;borohydride&nbsp;and&nbsp;direct&nbsp;ammonium&nbsp;borane&nbsp;fuel&nbsp;cells&nbsp;were&nbsp;systematically&nbsp;examined&nbsp;under&nbsp;different&nbsp;fuel&nbsp;concentrations,&nbsp;NaOH&nbsp;concentrations,&nbsp;temperatures,&nbsp;and&nbsp;flow&nbsp;rates.&nbsp;The&nbsp;obtained&nbsp;results&nbsp;demonstrated&nbsp;that&nbsp;the&nbsp;structural&nbsp;characteristic&nbsp;of&nbsp;the&nbsp;graphene&nbsp;supports&nbsp;significantly&nbsp;influenced&nbsp;the&nbsp;distribution&nbsp;of&nbsp;the&nbsp;bimetallic&nbsp;catalysts,&nbsp;electron&nbsp;transfer,&nbsp;and&nbsp;electrocatalytic&nbsp;activity.&nbsp;The&nbsp;electrochemical&nbsp;performance&nbsp;was&nbsp;found&nbsp;to&nbsp;vary&nbsp;depending&nbsp;on&nbsp;the&nbsp;type&nbsp;of&nbsp;graphene&nbsp;support,&nbsp;with&nbsp;the&nbsp;Au–Ni/GR&nbsp;and&nbsp;Au–Zn/N-GR&nbsp;electrodes&nbsp;exhibiting&nbsp;superior&nbsp;fuel&nbsp;cell&nbsp;performances.&nbsp;In&nbsp;contrast,&nbsp;although&nbsp;the&nbsp;Au–Co&nbsp;systems&nbsp;exhibited&nbsp;high&nbsp;electrocatalytic&nbsp;activity,&nbsp;hydrogen&nbsp;gas&nbsp;bubbles&nbsp;generated&nbsp;during&nbsp;hydrolysis&nbsp;adversely&nbsp;affected&nbsp;their&nbsp;fuel&nbsp;cell&nbsp;performance.</p><p> In&nbsp;conclusion,&nbsp;this&nbsp;study&nbsp;comprehensively&nbsp;demonstrated&nbsp;the&nbsp;applicability&nbsp;of&nbsp;graphene-supported&nbsp;Au-based&nbsp;bimetallic&nbsp;electrocatalysts&nbsp;as&nbsp;anode&nbsp;materials&nbsp;for&nbsp;direct&nbsp;borohydride&nbsp;and&nbsp;direct&nbsp;ammonium&nbsp;borane&nbsp;fuel&nbsp;cells.&nbsp;It&nbsp;was&nbsp;shown&nbsp;that&nbsp;the&nbsp;support&nbsp;material,&nbsp;catalyst&nbsp;composition,&nbsp;and&nbsp;operating&nbsp;conditions&nbsp;collectively&nbsp;play&nbsp;a&nbsp;decisive&nbsp;role&nbsp;in&nbsp;determining&nbsp;electrocatalytic&nbsp;performance.&nbsp;The&nbsp;findings&nbsp;of&nbsp;this&nbsp;study&nbsp;are&nbsp;expected&nbsp;to&nbsp;contribute&nbsp;to&nbsp;the&nbsp;development&nbsp;of&nbsp;high-performance,&nbsp;Pt-free&nbsp;anode&nbsp;electrocatalysts&nbsp;for&nbsp;alkaline&nbsp;fuel&nbsp;cells&nbsp;utilizing&nbsp;boron-based&nbsp;fuels.</p><p></p>

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