Size control of carbon-supported platinum nanoparticles made using polyol method for low temperature fuel cells

Abstract

Size control of carbon-supported platinum nanoparticles made using polyol method for low temperature fuel cells, Chemical Engineering Science, http://dx.doi.org/10.1016/j.ces. 2013.05.067 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractThe aim of this work is to present the results of the synthesis of Pt nanoparticles using the modified polyol method, using carbon black powder Vulcan XC-72R as a support. Two different techniques were used to synthesize the catalysts: a) fixing the initial concentration of the precursor (2 mM in H 2 PtCl 6 ) while adding the required amount of support to obtain different nominal loads of platinum; b) changing the initial concentration of the precursor to obtain altogether 10 wt.% nominal load of platinum. Catalysts were characterized using X-ray diffraction, transmission electron microscopy and cyclic voltammetry. The particles obtained ranged in sizes between 2.2 and 6.2 nm. These sizes were controlled by the initial concentration of the precursor. It has been found that the concentration of nanoparticles formed during synthesis was the same regardless of a) the initial concentration of the precursor and b) the amount of carbon support. In order to explain experimental results a new and simple statistical and geometrical treatment is used.

Cobalt modified two-dimensional polypyrrole synthesized in a flat nanoreactor for the catalysis of oxygen reduction

“…The best electrocatalyst used for this reaction is the Pt-based material Favilla et al, 2013;Liu et al, 2004); but the limited supply and prohibitive cost of Pt greatly impede the large-scale applications of these renewable energy technologies (Ding et al, 2013;Wu et al, 2011;Xie et al, 2014). Recent attentions gradually move to develop non-precious ORR catalysts, such as transition metal oxides (Andersen et al, 2015;Liang et al, 2011), heteroatom-doped carbon (Inamdar et al, 2013;Yang et al, 2014), and metal-N 4 materials (Kruusenberg et al, 2013;Wei et al, 2014).…”

Influence of Electrochemical Pretreatment Conditions of PtCu/C Alloy Electrocatalyst on Its Activity

“…Note that the average nanoparticle size determined from the TEM was about 5 nm, which significantly exceeded the value of the average crystallite diameter (Figure 2c) according to the XRD data. It is known that the average size of crystallites determined using XRD is usually smaller than the size of nanoparticles determined using TEM [40,41]. The main reasons for this difference are as follows: one nanoparticle can consist of several crystallites; the presence of an amorphous layer on the nanoparticle surface that is not detected using XRD; and there are different approaches to calculating the average crystallite size [42].…”

Stability and activity of platinum nanoparticles in the oxygen electroreduction reaction: is size or uniformity of primary importance?

“…The difference in the sizes of nanoparticles (crystallites) determined from the results of X-ray diffractometry and TEM is typical for nanostructured Pt/C materials. It is due to several factors: some nanoparticles can consist of several crystallites, so they have a larger size [19]; differences in the principles of calculation, which serve as the basis for the corresponding research methods [41]; a possible contribution of NP structural defects to the broadening of the X-ray diffraction pattern maxima [42], and problems related to the recognition of ultrasmall particles in TEM micrographs. The composition of the commercial catalysts JM20 and JM40 is similar to that of G20 and G40: the average crystallite size is 2.5 and 3.7 nm, and the average NP size is 2.7 and 3.7 nm, respectively.…”