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A Pd catalyst supported on a composite containing nitrogen-doped carbon-modified titanium oxides (Pd/NC-Ti-O), and was prepared for formic acid electrooxidation. According to structure and morphology characterizations, NC-Ti-O consists of a nitrogen-doped carbon, TiO2, Ti2O3, and Ti2O, and the Pd/NC-Ti-O catalyst has a smaller particle size and more uniform dispersion as compared to the Pd/Ti4O7 catalyst. Electrochemical measurements displayed that the Pd/NC-Ti-O catalyst possesses a better electrocatalytic activity and stability towards the electrooxidation of formic acid than Pd/Ti4O7. The improvement of catalytic activity is mainly ascribed to the higher content of metallic Pd and stronger resistance to CO poisoning caused by NC-Ti-O. [ABSTRACT FROM AUTHOR]

Modified Si nanoparticles were investigated as an anode material for lithium-ion batteries. The Si nanoparticle surfaces were modified with conductive, N-doped carbon layers and prepared by a simple pyrolysis process using an ionic liquid that contained nitrogen. After the heat treatment, the N-doped carbon layers were uniformly coated onto the Si nanoparticles. The smooth carbon layers connected the Si nanoparticles without any morphological changes. Si nanoparticles containing 34 wt.% N-doped carbon exhibited the best electrochemical performance with a capacity of ∼1145 mAh g and excellent capacity retention over 100 cycles. The high electrochemical performance was attributed to the N-doped carbon layers that improved the electrical conductivity and minimized the volume expansion associated with the alloy during cycling. [ABSTRACT FROM AUTHOR]

Doped mesoporous carbons comprising nitrogen, boron, and phosphorus (N, B, and P, respectively) were prepared as non-Pt catalysts for oxygen reduction reaction (ORR) in an acidic solution. The N-doped carbons were varied to increase their catalytic activity through by additionally doping of B and P. All the mesoporous carbons were synthesized by carbonizing polyaniline at 900 °C for the N species, while the B and P species were inserted into the carbon structure at the carbon growth step. The linear sweep voltammogram recorded in the acidic solution showed that the ORR activity of the N-doped carbon catalysts increased significantly after the addition of B. An approximately 19 % increase in the pyridinic N content at the carbon surface was observed, along with B-N-C moieties with a binding energy of 399.5 eV. The non-precious metal ORR catalysts were prepared via pyrolysis, with the insertion of an additional transition metal (iron, Fe). The deconvoluted X-ray photoelectron spectroscopy (XPS) results showed that the Fe-N peak was generated after the pyrolysis. The peak intensity of the quaternary N also increased compared with the pyridic and pyrrolic N, which indicates that Fe serves to catalyze the modification of N species. The numerical examinations showed that N- and B-doped mesoporous carbon (NBC) 1.5 % Fe had the highest limited current (4.94 mA/cm), with the B-doped carbon still the most active mesoporous carbon catalyst for ORR. As a result, it can be said that Fe positively contributes to the formation of graphitic N, which is known to be an active site for ORR. The cyclic voltammetry results showed that the peak area of the NBC 1.5 % Fe catalyst was larger than that of the N-doped mesoporous carbon (NC) 1.5 % Fe catalyst. It was concluded that B doping enhances the ORR activity and the stability of carbon materials even after 1000 cycles under acidic conditions. [ABSTRACT FROM AUTHOR]