215 research outputs found
Amorphous Pt@dCu/CNT catalyst for methanol elextrooxidation
A multi-walled carbon nanotube-supported, Pt decorated nano-sized amorphous PdCu alloy cores (denoted as Pt@PdCu/CNT)
catalyst with lower Pt loading is synthesized via a galvanic displacement reaction. The structure is examined using X-ray diffraction
(XRD) and transmission electron microscopy (TEM). The electrochemical activity of the Pt@PdCu/CNT catalyst is tested by
cyclic voltammogrametry (CV) and compared to that of PtRu/CNT catalysts. The results show that amorphous Pt@PdCu/CNT
catalyst exhibits better electro-catalytic performances for methanol oxidation than its crystalline counterpart.IS
Platinum overlaid PdCulr/C: an Improved Methanol Oxidation Elextrocatalyst
A platinum overlaid PdCuIr/C (Pt-PdIrCu/C) anodic catalyst for direct methanol fuel cell was prepared by a two-step reduction method. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) results show that the metal nano-particles had a large surface area and even distribution. The Pt mass activity of the catalyst was about 6.6 times larger than that of a Pt/C catalyst and 1.2 times larger than that of a Pt-PdCu/C catalyst. The high electrocatalytic activities could be attributed to the synergistic effect between Pt and PdIrCu.Web of Scienc
Beef-derived mesoporous carbon as highly efficient support for PtRuIr electrocatalysts and their high activity for CO and methanol oxidation
In this work, a low-cost and nitrogen-containing carbon with mesoporous pores and high surface area was synthesized by
carbonizing a natural biomass precursor, i.e. beef. It is found that the prepared material has excellent textural properties such as
high specific surface areas and large pore diameters. TEM images showed that the PtRuIr nanoparticles were well dispersed on
the surface of carbonized beef (C-Beef). PtRuIr/C-Beef was highly active for methanol electro-oxidation. PtRuIr/C-Beef showed
superior catalytic activity to PtRuIr/C, i.e. lower onset potential and higher oxidation current density. Cyclic voltammograms
of CO electro-oxidation showed that PtRuIr/C-Beef catalyst was kinetically more active for CO electro-oxidation than PtRuIr
deposited on conventional carbon support. The highly porous structure and low cost of carbonized beef can be widely used as
support for highly dispersed metal nanoparticles to increase their electrochemical performance as electrocatalysts
Selenium-functionalized carbon as a support for platinum nanoparticles with improved electrochemical properties for the oxygen reduction reaction and CO tolerance
Using selenium-functionalized carbon as supports, platinum nanoparticles were uniformly dispersed on the carbon surface, and
showed improved electrochemical properties for the oxygen reduction reaction. At the same time the CO tolerance is improved. The
method provides a new route for functionalization of the carbon surface on which to disperse noble metal nanoparticles for use as
electrocatalysts in the oxygen reduction reaction.Web of Scienc
Selenium-functionalized carbon as a support for platinum nanoparticles with improved electrochemical properties for the oxygen reduction reaction and CO tolerance
Using selenium-functionalized carbon as supports, platinum nanoparticles were uniformly dispersed on the carbon surface, and
showed improved electrochemical properties for the oxygen reduction reaction. At the same time the CO tolerance is improved. The
method provides a new route for functionalization of the carbon surface on which to disperse noble metal nanoparticles for use as
electrocatalysts in the oxygen reduction reaction.Web of Scienc
A CCBM-based generalized GKB iterative regularizing algorithm for inverse Cauchy problems
This paper examines inverse Cauchy problems that are governed by a kind of
elliptic partial differential equation. The inverse problems involve recovering
the missing data on an inaccessible boundary from the measured data on an
accessible boundary, which is severely ill-posed. By using the coupled complex
boundary method (CCBM), which integrates both Dirichlet and Neumann data into a
single Robin boundary condition, we reformulate the underlying problem into an
operator equation. Based on this new formulation, we prove the existence of a
unique solution even in cases with noisy data. A Golub-Kahan bidiagonalization
(GKB) process together with Givens rotation is employed for iteratively solving
the proposed operator equation. The regularizing property of the developed
method, called CCBM-GKB, and its convergence rate results are proved under a
posteriori stopping rule. Finally, a linear finite element method is used for
the numerical realization of CCBM-GKB. Various numerical experiments
demonstrate that CCBM-GKB is a kind of accelerated iterative regularization
method, as it is much faster than the classic Landweber method
Palygorskite hybridized carbon nanocomposite as a high-performance electrocatalyst support for formic acid oxidation
A nanocomposite, in which acid-treated palygorskite was hybridized with carbon, was prepared and designed as an efficient
support for electrocatatlysts. Pd nanoparticles were deposited on the hybrid support as an electrocatalyst for formic acid oxidation.
The hybrid supports and electrocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy
(TEM) and X-ray photoelectron spectroscopy (XPS).TEMandXRDresults showed that acid treatment had an effective impact on
the morphology of palygorskite, but did not destroy its architecture. XPS results indicated that the introduction of palygorskite
resulted in a negative shift of binding energy of Pd deposited on it. The electrochemical results showed that the addition of
palygorskite into the carbon facilitated the formation ofOHads orOads on the surface of Pd/C-PLS, and further improved the formic
acid electrooxidation activity. Therefore, considerable improvements in electrocatalytic activity toward formic acid oxidation was
achieved by using this hybrid support when compared with conventional carbon support, suggesting that the introduction
of SiO2-based porous palygoriskite was an excellent and cost-efficient way to improve the electrocatalytic performance of carbon
support.Web of Scienc
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