Catalysis and Reaction Engineering Commons^™

Synthesis And Electrocatalysis Of Pdcu Alloy Nanocrystals, Hai-Bin Wu, Rui-Zhong Zhang, Wei Chen

Journal of Electrochemistry

Monodispersed PdCu alloy nanoparticles were synthesized by co-reduction of Cu(acac)2 and Pd(acac)2 with 1, 2-hexadecanediol. The spherical and popcorn-like shapes of PdCu alloy nanoparticles were obtained by changing the ratios of mixed surface protecting ligands of 1-octadecene, and oleylamine or oleic acid. TEM and XRD measurements showed that both PdCu nanoparticles are alloy nanocrystals dominated with (111) planes and the average sizes are 12.7 ± 0.18 and 20.4 ± 0.31 nm for he spherical and popcorn-like PdCu nanoparticles, respectively. The electrocatalytic activities of the PdCu nanocrystals for formic acid oxidation were evaluated by electrochemical cyclic voltammetry (CV). The result showed …

Electrochemical Synthesis Of Hierarchical Dendritic Polyaniline Nanostructures, Shao-Huang Weng, Jian-Zhang Zhou, Zhong-Hua Lin, Xin-Hua Lin

Journal of Electrochemistry

In this work, the p-TSA doped and hierarchical dendritic nanostructured polyanilines (PANI) have been prepared by potentiostatic electropolymerization without using any templates at room temperature. The mechanism of the polymerization has been discussed according to the electrodeposition curves. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to confirm the formation of uniform hierarchical dendritic structure on PANI. UV-Vis spectroscopy (UV-Vis) and infrared spectroscopy (FTIR) proved that the prepared PANI is in the form of emeraldine salt. The templateless electrodeposition method is simple, easy to operate, can be applied to fabricate other nanostructures of conducting polymers.

Comparison Of Biomass To Bio-Oils Reactor Systems: Direct Conversion Vs. Companion Coal Gasification, Alexandra Eicher

Honors Theses and Capstones

It is well known that the United States’ dependence on crude-oil negatively affects its economy, safety, and environment. To alleviate these negative consequences, a more economical and environmentally-friendly source of fuel, such as biomass, should be explored. The conversion of biomass to bio-oils involves the pyrolysis of biomass at about 500°C, thus requiring a great deal of heat. This heat source could be the excess waste heat from a coal gasifier.

As such, this report specifies the design of an industrial plant that produces bio-oils from biomass by using the waste heat from a coal gasifier. It is designed to …

An In Situ Ftir Spectroelectrochemical Study On Methanol Oxidation At Pt-Mo2C/Gc Catalyst, Hai-Ping Huang, Xi-Yu Yao, Pei-Kang Shen

Journal of Electrochemistry

A 40% Pt on Mo₂C/GC catalyst has been prepared by ion exchange method. The mechanism of methanol electrooxidation on Pt-Mo₂C/GC and commercial Pt/C catalysts in acidic media was studied by cyclic voltammetry, XRD measurements and in-situ Fourier transform infrared spectroelectrochemistry. The results revealed that the Pt nanoparticles were uniformly dispersed on Mo₂C/GC with an average particle size of 3 nm. The cyclic voltammetric and chronopotentiometric experiments indicated that Pt-Mo₂C/GC catalyst exhibited a better performance for methanol oxidation than that of Pt/C in acid solution. A negative shift over 90 mV of the …

Oxygen Reduction Reaction On Glycin Modified Pt(111) Electrode, Ming-Fang Li, Jing Kang, Ling-Wen Liao, Yan-Xia Chen, Shen Ye

Journal of Electrochemistry

O

xygen reduction reaction (ORR) on glycin (NH₂CH₂COOH) modified Pt(111) electrode has been investigated using hanging meniscus rotating disk electrode system (HMRD) in 0.05 mol•L^-1 H₂SO₄ and 0.1 mol•L^-1 HClO₄ solutions, respectively. Cyclic voltammograms of the glycin modified Pt (111) electrode measured in 0.05 mol•L^-1 H₂SO₄ solution similar to that of CN^- modified Pt(111) electrodes, demonstrating that sulfate adsorption is strongly inhibited at the glycin modified Pt(111). From the polarization curve of ORR recorded in 0.05 mol•L^-1 H₂SO₄ solution, it is …

Effect Of Ti/Pbo2 Electrodes Doped With Different Elements On Electrocatalytic Oxidation Characteristics Of Phenol, Xiao-Lei Liu, Yuan-Yuan Dan, Hai-Yan Lu, Hai-Bo Lin, Ming-Li Ouyang, Chuan-Jun Yun

Journal of Electrochemistry

Three types of electrodes, namely, Ti/PbO₂, F-doped PbO₂ (Ti/PbO₂-F) and nano-Co₃O₄-doped PbO₂ (Ti/PbO₂+Nano-Co₃O₄) electrodes, were prepared by electro-deposition method on the Ti substrate with the interlayer of SnO₂-Sb₂O₅. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study the compositions, structures and film morphologies of the electrodes. Electrocatalytic oxidation characteristics to phenol on the prepared electrodes were investigated by electrochemical method. The experimental results showed that compared with the Ti/PbO₂ electrode, the potentials of oxygen …

A Dft Calculation Screening Of Pt-Based Bimetallic Catalysts For Oxygen Reduction, Li-Hui Ou, Sheng-Li Chen

Journal of Electrochemistry

Developing Pt-lean catalysts for oxygen reduction reaction (ORR) is the key for large-scale application of proton exchange membrane fuel cell (PEMFC). In this paper, we have proposed a multiple-descriptor strategy for screening efficient and durable ORR alloy catalysts of low Pt content. We argue that an ideal Pt-based bimetallic alloy catalyst for ORR should possess simultaneously negative alloy formation energy, negative surface segregation energy of Pt and a lower oxygen binding ability than pure Pt. By performing detailed DFT calculations on the thermodynamics, surface chemistry and electronic properties of various Pt-M alloys (M refers to non-precious transition metals in the …

Microkinetic Modeling And Analysis Of Ethanol Partial Oxidation And Reforming Reaction Pathways On Platinum At Short Contact Times, Maura A. Koehle

Master's Theses

No abstract provided.

Adiabatic Flame Temperature For Combustion Of Methane Ii, Rebeca Pupo

Undergraduate Journal of Mathematical Modeling: One + Two

We calculate the adiabatic flame temperature of a mixture of methane and oxygen in the presence of a diluent gas then determine the mole fractions of methane without respect to nitrogen and solve for the moles of oxygen present. Knowing the moles of methane and oxygen, allows us to calculate the moles of nitrogen present at four constant mole fractions of nitrogen, and the adiabatic flame temperature is determined from the energy released by the reaction. Lastly, we produce several graphs to compare the adiabatic flame temperatures at different mole fractions of nitrogen.

Partial Oxidation Of Ethane To Acetic Acid On Titania Supported Movnbpd Catalyst, Yousef S. Al-Zeghayer, Abdulrhman S. Al-Awadi, Baba Y. Jibril, Moustafa A. Soliman, Sulaiman Al-Mayman

Chemical Engineering

Partial oxidation of ethane was studied on unsupported and supported Mo-V-Nb oxides. Different grades of titania (Crystal-AF4.60, AF7.70 and AF12.5 and Degussa P25) were explored as supports. Samples of the catalyst were characterized using XRD, SEM and BET surface area. The reaction was carried out at 200-275°C and 200 psi. At ethane conversion (6%), unsupported samples exhibited selectivities to ethylene and acetic acid of 76 and 23%, while for Degussa P25-supported sample, the values were 54 and 35%, respectively. Addition of Pd (0.196%) led to an increase in selectivity to acetic acid of 75%.

Self-Assembling Of Gold Nanoparticles Array For Electro-Sensing Applications, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

A colloidal solution of citrate-stabilized gold nanoparticles (AuNPs) with an average size of ca. 2.6 nm has been prepared, characterized and further implemented in electro-sensing applications. This colloidal solution of AuNPs has been prepared via the reduction of NaAuCl4 with sodium tetrahydroborate (NaBH4) using trisodium citrate as a stabilizer. The optical properties of this solution have been studied with UV–Vis spectroscopy. Next, these AuNPs have been immobilized onto a polycrystalline Au (poly-Au) electrode with the assistance of benzenedimethanethiol (BDMT), which served as a binder. Attention has been taken to ensure the formation of a compact impermeable layer of BDMT on …

The Effects Of Ceria Addition On Aging And Sulfation Of Lean Nox Traps For Stand Alone And Lnt-Scr Applications, Vencon G. Easterling

Theses and Dissertations--Chemical and Materials Engineering

THE EFFECTS OF CERIA ADDITION ON AGING AND SULFATION OF LEAN NO_x TRAPS FOR STAND ALONE AND LNT-SCR APPLICATIONS

Model powder and fully formulated monolithic lean NO_x trap (LNT) catalysts were used to investigate the effect of ceria on desulfation behavior. Temperature-programmed reduction (TPR) experiments (model catalysts) showed each of the oxide phases present is able to store sulfur and possesses distinct behavior (temperature at which desulfation occurs). La-CeO₂ or CeO₂-ZrO₂-containing samples (monoliths) showed a greater resistance to deactivation during sulfation and required lower temperatures to restore the NO_x storage efficiency to …