We report surface-bound growth of single-wall carbon nanotubes (SWNTs) at temperatures as low as 350 degrees C by catalytic chemical vapor deposition from undiluted C2H2. NH3 or H2 exposure critically facilitates the nanostructuring and activation of sub-nanometer Fe and Al/Fe/Al multilayer catalyst films prior to growth, enabling the SWNT nucleation at lower temperatures. We suggest that carbo...

Understanding Fe deposition in fluid catalytic cracking (FCC) catalysis is critical for the mitigation of catalyst degradation. Here we employ soft X-ray ptychography to determine at the nanoscale the distribution and chemical state of Fe in an aged FCC catalyst particle. We show that both particle swelling due to colloidal Fe deposition and Fe penetration into the matrix as a result of precrac...

carbon nanotubes were synthesized over a series of zn-containing fe/alumina catalysts by chemical vapor deposition method at two reaction temperatures of 850 and 950 °c using methane as a carbon source. catalysts were synthesized by keeping fe concentration constant and varying zn concentration to study the effects of zn. the catalysts were characterized using x – ray powder diffraction and n2 ...

A two-stage pyrolysis−catalytic steam reforming process was used with mesoporous MCM-41 supported iron and nickel bimetallic catalysts for hydrogen-rich syngas production from a simulated mixture of waste plastics. Different Fe/Ni weight ratios (00:20, 05:15, 10:10, 05:15, and 20:00) have been investigated to determine the influence on hydrogen production. The results showed that the presence o...

In this work, a non-precious metal catalyst consisting of Co9S8 nanoparticles surrounded with nitrogen-doped graphene-like carbon (Co9S8-N-C) was developed for oxygen reduction in alkaline media. Improved activity has been measured with the Co9S8-N-C catalyst relative to Pt/C and a non-precious metal catalyst based on Fe instead of Co (Fe-N-C). An extensive physical characterization, including ...

We report the one-step synthesis of a highly active hierarchical Fe/ZSM-5 zeolite catalyst with a strongly improved lifetime in the selective hydroxylation of benzene to phenol with nitrous oxide; compared to the best Fe/ZSM-5 catalyst, the turnover number after 24 h on stream is almost four times higher.

The adsorption performance of Fe/ZSM-5 catalyst has been investigated in the SCR of NOx with propylene as the reducing agent. Freudlich equation was found to fit the adsorption isotherm satisfactorily if the system dispersion is considered. Fe/ZSM-5 catalyst showed reasonable NO adsorption capacity. The study on the influence of reaction temperature, gas space velocity and gas composition on th...

Fe (III)-catalyzed ozonation yielded better degradation rate and extent of COD (Chemical Oxygen Demand) or oxalic acid as compared with oxidation by ozone alone. Two parameters with strong effects on the efficiency of ozonation are pH of the solution and the catalyst (Fe(3+)) dosage. The existence of a critical pH value determining the catalysis of Fe (III) in acid conditions was observed in ph...

The catalysis of n-butane isomerization over iron-promoted tungstated zirconia (F1.2WZ) and platinum–iron-promoted tungstated zirconia (P/F1.2WZ) catalysts was studied and correlated to the catalyst characterization results. In the singly promoted F1.2WZ catalyst, we suggest that the iron species promotes the n-butane isomerization reaction through a redox effect. The formation of W–O–Fe linkag...

The mechanisms of the few known molecular nitrogen-fixing systems, including nitrogenase enzymes, are of much interest but are not fully understood. We recently reported that Fe-N2 complexes of tetradentate P3(E) ligands (E = B, C) generate catalytic yields of NH3 under an atmosphere of N2 with acid and reductant at low temperatures. Here we show that these Fe catalysts are unexpectedly robust ...