N-doped carbon, a promising alternative to Pt catalyst for oxygen reduction reactions (ORRs) in acidic media, is modified order increase its catalytic activity through the additional doping of B and P at carbon growth step. This alters electrical, physical, morphological properties carbon. The B-doping reinforces sp2-structure graphite increases portion pyridinic-N sites lattice, whereas P-doping enhances charge delocalization atoms produces structures with many edge sites. These electrical...

Nitrogen (N)-doped carbon materials were shown in recent studies to have promising catalytic activity for oxygen reduction reaction (ORR) as a metal-free alternative platinum, but the underlying molecular mechanism or even active sites high efficiency are still missing controversial both experimentally and theoretically. We report here results of periodic density functional theory (DFT) calculations about ORR at edge graphene nanoribbon (GNR). The structure doped-N near enhance adsorption,...

The catalytic removal of nitrogen oxide (NOx) under lean‐burn conditions is one the most important targets in catalysis research. Some lean‐NOx control technologies such as direct decomposition NOx, NOx storage‐reduction (NSR), and selective reduction (SCR) using different reducing agents (diesel soot, NH3, or hydrocarbon) are described. reaction mechanism NSR, which promising technology, together with some novel NSR catalysts discussed. mechanisms SCR by hydrocarbon (HC‐SCR) were classified...

Graphene has been highlighted recently as a promising material for energy conversion due to its unique properties deriving from two-dimensional layered structure of sp2-hybridized carbon. Herein, N-doped graphene (NGr) is developed application in oxygen reduction reactions (ORRs) acidic media, and additional doping B or P into the NGr attempted enhance ORR performance. The exhibits an onset potential 0.84 V mass activity 0.45 mA mg−1 at 0.75 V. However, B, N- (BNGr) P, (PNGr) show potentials...

Mn–Ce–Ti mixed-oxide catalyst prepared by the hydrothermal method was investigated for selective catalytic reduction (SCR) of NOx with NH3 in presence oxygen. It found that environmentally benign exhibited excellent NH3-SCR activity and strong resistance against H2O SO2 a broad operation temperature window, which is very competitive practical application controlling emission from diesel engines. On basis characterization, dual redox cycles (Mn4+ + Ce3+ ↔ Mn3+ Ce4+, Mn4+ Ti3+ Ti4+) amorphous...

Abstract Electrocatalytic CO 2 conversion into fuel is a prospective strategy for the sustainable energy production. However, still many parts of catalyst such as low catalytic activity, selectivity, and stability are challenging. Herein, hierarchical hexagonal Zn showed highly efficient and, more importantly, stable performance an electrocatalyst selectively producing CO. Moreover, we found that its high selectivity attributed to morphology. In electrochemical analysis, (101) facet...

Nitrogen doped graphene were prepared via exfoliated graphite oxide. This exhibited significantly high oxygen reduction activity. High electric conductivity, surface area, large amount of edge sites and pyridinic N site in rGS (reduced sheets) contribute to the ORR (oxygen reaction) The showed a potential replace expensive Pt for reaction PEMFC.

Abstract Catalysis is a key technology for the synthesis of renewable fuels through electrochemical reduction CO 2 . However, successful still suffers from lack affordable catalyst design and understanding factors governing catalysis. Herein, we demonstrate that conversion selectivity on Sn (or SnO x /Sn) electrodes correlated to native oxygen content at subsurface. Electrochemical analyses show reduced electrode with abundant species effectively stabilizes .− intermediate rather than clean...

N-doped carbon materials are considered as next-generation oxygen reduction reaction (ORR) catalysts for fuel cells due to their prolonged stability and low cost. However, the underlying mechanism of these has been only insufficiently identified, preventing rational design high-performing catalysts. Here, we show that first electron is transferred into O2 molecules at outer Helmholtz plane (ET-OHP) over a long range. This in sharp contrast conventional belief adsorption must precede ET step...

A new strategy for enhancing the oxygen reduction reaction (ORR) activity of carbon-based catalysts in acidic media is proposed and characterized; consists modifying ORR through dual doping nitrogen phosphorus into carbon. The P, N-doped carbon prepared via pyrolysis a mixture composed dicyandiamide (DCDA), phosphoric acid, cobalt chloride, iron chloride at 900 °C under an Ar atmosphere. P-doping induces uneven surface with many open edged sites morphology increases area from 108.1 to 578.8...

To achieve sustainable utilization of solar energy, development an efficient photocatalyst for water oxidation, the driving force reductive fuel formation, is strongly needed. Herein, composite photocatalysts with bismuth vanadate (BiVO4) and sulfur-doped graphitic carbon nitride (SCN) are developed by using a one-pot impregnated precipitation method. Fourier transform infrared X-ray photoelectron spectroscopy analyses demonstrate that surface SCN oxidized during impregnation becomes...

Abstract Alcaligenes eutrophus NCIMB 11599 was cultivated to produce poly(3‐hydroxybutyric acid) (PHB) from glucose by the automatic fed‐batch culture technique. The concentration of broth controlled at 10 20 g/L two methods: using exit gas data obtained a mass spectrometer and an on‐line analyzer. effect ammonium limitation on PHB synthesis different phases studied. final cell concentration, productivity increased as ammonia feeding stopped higher concentration. High concentrations (121...

Carbon nanotubes (CNTs), either single wall carbon (SWNTs) or multiwall (MWNTs), can improve the thermoelectric properties of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT : PSS), but it requires addition 30–40 wt% CNTs. We report that figure merit (ZT) value PEDOT PSS thin film for property is increased about 10 times by incorporating 2 graphene. films containing 1, 2, 3 graphene are prepared solution spin coating method. X-ray photoelectron spectroscopy (XPS) and Raman...

Heteroatom (nitrogen and sulfur)-doped carbons were synthesized via the pyrolysis of composites composed iron chloride, cobalt chloride five different amino acids (alanine, cysteine, glycine, niacine valine), their electrocatalytic activity towards oxygen reduction reactions (ORR) compared with each other for fuel cell applications. In all prepared catalysts, carbon was doped by nitrogen, and, in particular, a catalyst from cysteine dual-doped nitrogen sulfur. Among showed highest onset...

An environmentally benign Cu–Ce–Ti oxide catalyst exhibited excellent NH3-SCR activity, high N2 selectivity and strong resistance against H2O SO2 with a broad operation temperature window. The dual redox cycles (Cu2+ + Ce3+ ↔ Cu+ Ce4+, Cu2+ Ti3+ Ti4+) play key roles for the superior catalytic deNOx performance.

Phosphorus and/or sulfur are additionally doped into N-doped carbon (NDC) using phosphoric acid and cysteine. The resulting catalysts demonstrate excellent oxygen reduction activities coupled with high stabilities in acidic media. Specially, additional S-doping NDC reveals nearly 2.5 times higher activity than that of at 0.75 V (vs. RHE).

Selective catalytic reduction of NOx by hydrogen (H2-SCR) in the presence oxygen has received much attention as a potential technology for reducing emissions. A lot research been done order to understand reaction mechanism H2-SCR and some possible mechanisms have proposed. These can be classified into two categories: NO adsorption/dissociation oxidation–reduction mechanisms. Based on discussion mechanism, influence nature noble metal, catalyst support, preparation method, promoters...

Methanol-tolerant cathode materials for use in direct-methanol fuel cells are composed of ordered mesoporous carbon with walls studded ultrafine Pt nanoclusters. The material (see Figure), PtC regularly interconnected nanocomposite arrays, is prepared by pyrolysis and platinum precursors silica templates such as SBA-15.

Improving the electrocatalytic activity and durability of Pt-based catalysts with low Pt content toward oxygen reduction reaction (ORR) is one main challenges in advancing performance polymer electrolyte membrane fuel cells (PEMFCs). Herein, a designed synthesis well-defined Pd@Pt core-shell nanoparticles (NPs) controlled shell thickness 0.4-1.2 nm by facile wet chemical method their performances for ORR as function are reported. NPs predetermined structural parameters were prepared situ...