催化学报
催化學報
최화학보
CHINESE JOURNAL OF CATALYSIS
2015年
2期
175-180
,共6页
姜鲁华%唐琪雯%刘静%孙公权
薑魯華%唐琪雯%劉靜%孫公權
강로화%당기문%류정%손공권
氧还原反应路径%碱性电解质%碳载氧化锰电催化剂
氧還原反應路徑%堿性電解質%碳載氧化錳電催化劑
양환원반응로경%감성전해질%탄재양화맹전최화제
Oxygen reduction reaction pathway%Alkaline electrolyte%Carbon-supported electrocatalyst%Manganese oxide
氧还原反应(ORR)是一个复杂的过程,尤其在碱性电解液中,炭载型催化剂表面的ORR路径尤为复杂,因为碳本身可以催化ORR以二电子转移过程发生,产生过氧化氢,继而过氧化氢或者发生化学分解生成氧气(HODR),或者发生电化学还原生成OH–(HORR)。本文详细研究了ORR在常用氧化锰催化剂表面的反应路径。通过比较HODR和HORR的转换频率发现,尽管利用旋转环盘电极方法得到的表观电子转移数接近4,真实的ORR主要是2电子过程,反应生成的过氧化氢继而大部分发生化学分解生成氧气。该结果有助于理解碱性电解质中炭载型过渡金属氧化物电催化剂对ORR的催化行为。
氧還原反應(ORR)是一箇複雜的過程,尤其在堿性電解液中,炭載型催化劑錶麵的ORR路徑尤為複雜,因為碳本身可以催化ORR以二電子轉移過程髮生,產生過氧化氫,繼而過氧化氫或者髮生化學分解生成氧氣(HODR),或者髮生電化學還原生成OH–(HORR)。本文詳細研究瞭ORR在常用氧化錳催化劑錶麵的反應路徑。通過比較HODR和HORR的轉換頻率髮現,儘管利用鏇轉環盤電極方法得到的錶觀電子轉移數接近4,真實的ORR主要是2電子過程,反應生成的過氧化氫繼而大部分髮生化學分解生成氧氣。該結果有助于理解堿性電解質中炭載型過渡金屬氧化物電催化劑對ORR的催化行為。
양환원반응(ORR)시일개복잡적과정,우기재감성전해액중,탄재형최화제표면적ORR로경우위복잡,인위탄본신가이최화ORR이이전자전이과정발생,산생과양화경,계이과양화경혹자발생화학분해생성양기(HODR),혹자발생전화학환원생성OH–(HORR)。본문상세연구료ORR재상용양화맹최화제표면적반응로경。통과비교HODR화HORR적전환빈솔발현,진관이용선전배반전겁방법득도적표관전자전이수접근4,진실적ORR주요시2전자과정,반응생성적과양화경계이대부분발생화학분해생성양기。해결과유조우리해감성전해질중탄재형과도금속양화물전최화제대ORR적최화행위。
The oxygen reduction reaction (ORR) is a complex process. This is particularly the case for car‐bon‐supported electrocatalysts in alkaline electrolytes, because carbon can catalyze the ORR via a two‐electron transfer to generate hydroperoxide (HO2?), which subsequently undergoes either chemical decomposition to generate O2 and OH? (HODR) or electrochemical reduction to OH?(HORR). In this study, we elucidated the ORR pathway on a series of carbon‐supported manganese oxides, which have been extensively studied as electrocatalysts in alkaline electrolytes. A compari‐son of the turnover frequencies of the HODR and HORR showed that although an apparent four‐electron transfer process was identified when the HO2?yield was measured using the rotating ring disk electrode technique, the real ORR pathway involved a two‐electron transfer process to generate HO2?, with subsequent chemical decomposition of HO2?. These results will help us to un‐derstand the intrinsic catalytic behavior of carbon‐supported transition‐metal oxides for the ORR in alkaline electrolytes.