Carbon-riveted Pt catalyst supported on nanocapsule MWCNTs–Al2O3 with ultrahigh stability for high-temperature proton exchange membrane fuel cells

Abstract

Pt catalyst supported on nanocapsule MWCNTs-Al(2)O(3) (multi-walled carbon nanotubes, MWCNTs) catalyst has been prepared by microwave-assisted polyol process (MAPP). The results of electrochemical measurements show that the nanocapsule Pt/MWCNTs-Al(2)O(3) catalyst has higher activity due to more uniform dispersion and smaller size of Pt nanoparticles, and higher stability ascribed to the stronger metal-support interaction (SMSI) between Pt nanoparticles and nanocapsule support than in Pt/MWCNTs. Furthermore, the carbon-riveted nanocapsule Pt/MWCNTs-Al(2)O(3) catalyst has been designed and synthesized on the basis of in situ carbonization of glucose. The physical characteristics such as X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) have indicated that α-Al(2)O(3) indeed entered into the inside of the MWCNTs and formed a nanocapsule support of MWCNTs with α-Al(2)O(3) as stuffing. The accelerated potential cycling tests (APCT) show that carbon-riveted nanocapsule Pt/MWCNTs-Al(2)O(3) possesses 10 times the stability of Pt/C and has 4.5 times the life-span of carbon-riveted Pt/TiO(2)-C reported in our previous work. The significantly enhanced stability for carbon-riveted nanocapsule Pt/MWCNTs-Al(2)O(3) catalyst is attributed to the reasons as follows: the inherently excellent mechanical resistance and stability of α-Al(2)O(3) and MWCNTs in acidic and oxidative environments; SMSI between Pt nanoparticles and the nanocapsule support; the anchoring effect of the carbon layers formed during the carbon-riveting process (CRP); the increase of Pt(0) composition during CRP.

Real‐space observation of strong metal‐support interaction: state‐of‐the‐art and what's the next

“…For instance, If the support surface is SrTiO 3 (001), the encapsulated outmost layer is identified as a non-commensurate TiO x (Silly & Castell, 2005). Considering that the noble metal, particularly Pt, supported by the conventional TiO 2 and modified supports, has been receiving wide attention in terms of the SMSI effect, as shown in Table 1 (Liu et al, 2010;Zhu et al, 2011;Bidaoui et al, 2012;Jiang et al, 2012;Yao et al, 2012;Chang et al, 2013;An et al, 2014;Jia et al, 2014b;Kumar & Ramani, 2014). The relevant characterization includes TEM coupled with other methods, such as XPS, XRD, etc.…”

Biohydrogen for a New Generation of H2/O2 Biofuel Cells: A Sustainable Energy Perspective

“…These metals are, however, very expensive (average price is 40 E/g against 2 E/g for Ru for example [from http://www.platinum.matthey.com/prices/price-charts/]), are available in low amounts on earth (37 ppb in the Earth's crust), and are nonbiodegradable. Extensive research has aimed at decreasing the Pt content (for a review see [5] ), such as: 1) nanostructuration of the catalysts, [6,7] 2) use of alloys or heterostructures, [8][9] 3) nanostructuration and treatment of the carbon support, [10][11][12][13] 4) use of noncarbon matrixes such as conducting polymers, [14] and 5) use of semiconductive transitionmetals. [15] Furthermore, platinum catalysts are readily poisoned by very low levels of CO and S (0.1 % of CO is sufficient to decrease one hundred fold the catalytic activity of Pt in ten minutes), thus requiring extensive H 2 purification.…”

Methanol oxidation on Pt/CeO2@C–N electrocatalysts prepared by the in-situ carbonization of polyvinylpyrrolidone

“…It also can be seen that the binding energy of Pt(0) for Pt/CeO 2 -20 wt% shows a higher shift about 0.23 eV in comparison with Pt/CeO 2 , which is likely ascribed to the reason that the formation of C-N bonds on the support surface can intensify the electron withdrawing effect against Pt and strengthen the metal-support interaction between Pt nanoparticles and the support [31]. And another critical found is that the content of functional species Pt(0) in the Pt/CeO 2 -20 wt% catalyst increases by 9.43 %, while Pt(IV) decreased by 4.99 % compared with Pt/CeO 2 , which leads to greatly enhanced durability for Pt/CeO 2 coated with PVP catalyst, [32] so it can be concluded that the nitrogen-doped carbon is successfully incorporated onto CeO 2 .…”