【原文摘要】
一氧化碳中毒是鉑基催化劑應用于電催化過程的主要障礙之一。本文基于DFT+D3 計算,通過B 和N 摻雜石墨 烯并改變團簇尺寸以減弱Pt 催化劑的CO 中毒現象。計算得到了能量上最有利的Ptn/X-石墨烯(X = C, B, N; n = 1?6, 13)結構,且Ptn 和X-石墨烯之間的結合能依賴于團簇尺寸與載體,順序為:Ptn/B-g > Ptn/N-g > Ptn/C-g。低 配位及突出的原子作為主要活性位點參與反應。由于d 帶中心的位置和界面引起的電子轉移,中等大小團簇(n = 4?6)能有效抑制CO 中毒,具有優異的CO 氧化性能。此外揭示了以第二次CO2 解吸為速控步的E-R 機制主導 的反應路線。Ptn/B-g (n = 4,5,6)對應的活化能壘分別為0.53、0.61 和0.56 eV。這項工作為抗CO 中毒的Ptn/Xg 催化劑在燃料電池中的應用與設計提供了理論指導。
【圖文速覽】
Fig. 1 Configurations of Pt clusters adsorption on pristine and B/N-doped graphenes, where gray, green, blue, and dark bluerepresent C, B, N, and Pt, respectively
Fig. 2 Normalized total DOS and local DOS of Pt13/X-g X = (C,B, N) with an energy scale from –8.0 to 8.0 eV, wherecontribution from B and N around Fermi level (–8.0 to 0 eV)are energy 20 times in Pt13/B-g and Pt13/N-g, respectively, andFermi level is shift to zero
Fig. 3 Interaction between Pt catalyst and doped graphene: a binding energy (Eb); b AC between Pt atom and C/B/N; c average netcharge (DQ(e)) of Pt (± denotes gaining/losing electrons); d geometrical parameters of bond length of Pt-C and Pt-B/N
Fig. 4 a Adsorption energy between CO/O2 and Ptn/X-g (X = B, N, and C); b positions of d-band center calculated for Ptn/X-g (X = B,N and C) clusters as a function of cluster size; c illustration of energy level shifts between O2 and Ptn/X-g (X = C, B, N); relationshipbetween O2 adsorption energy and parameters: d QO2, e hPt, and f CN; relationship between CO adsorption energy and parameters:g CN, h hPt, and i n
Fig. 5 Potential energy curves for CO oxidation promoted by a Pt4/B-g, b Pt5/B-g, and c Pt6/B-g along Path 1 (black line) and Path 2(red line), respectively, where energies include zero-point energy corrections
審核編輯 :李倩
-
燃料電池
+關注
關注
26文章
957瀏覽量
95159 -
石墨烯
+關注
關注
54文章
1549瀏覽量
79557 -
催化劑
+關注
關注
0文章
92瀏覽量
10294
原文標題:Rare Metals:依賴于尺寸和載體的 Ptn/X-石墨烯催化劑(X = C、B、N)減弱 CO 中毒
文章出處:【微信號:清新電源,微信公眾號:清新電源】歡迎添加關注!文章轉載請注明出處。
發布評論請先 登錄
相關推薦
評論