This work focuses on the nucleation and growth mechanisms of GaN nanowires (NWs) by molecular beam epitaxy (MBE). The two main novelties of this study are the intensive employment of in-situ techniques and the direct comparison of selfinduced and catalyst-induced NWs. On silicon substrates, GaN NWs form in MBE without the use of any external catalyst seed. On sapphire, in contrast, NWs grow und...

The aromatic rings of polystyrene (PS) were hydrogenated in decahydronaphthalene (DHN) expanded with supercritical carbon dioxide (scCO2). Conducting the hydrogenation in scCO2-DHN offers the benefits of improved transport properties, specifically lower solution viscosity and a higher PS diffusion coefficient. Various Pd catalysts are effective for hydrogenating the aromatic rings of PS at temp...

kinetic monte carlo simulation was applied to investigation of kinetics and mechanism of oxalic acid degradation by direct and heterogeneous catalytic ozonation. la-containing perovskites including lafeo3, lanio3, lacoo3 and lamno3 was studied as catalyst for oxalic acid ozonation. the reaction kinetic mechanisms of each abovementioned catalytic systems has been achieved. the rate constants val...

As stock of crude oil is limited, new resources for fuel and petrochemicals are required to be developed. Natural gas or biogas can be easily converted into methanol which can be converted into gasoline and olefins. This study uses zeolite catalyst (ZSM-5) and its modification by Ni to convert methanol to hydrocarbons (MTH). Catalysts are studied at different temperatures and at different loadi...

The growth of vertically aligned carbon nanotubes using a direct current plasma enhanced chemical vapor deposition system is reported. The growth properties are studied as a function of the Ni catalyst layer thickness, bias voltage, deposition temperature, C2H2:NH3 ratio, and pressure. It was found that the diameter, growth rate, and areal density of the nanotubes are controlled by the initial ...

A combined catalyst and sorbent was developed for reacting CO with steam to produce H2 in a single reaction stage at 600 °C by employing the water gas shift (WGS) reaction. The combined material was in the form of spherical pellets where each pellet consisted of a CaO core for absorbing byproduct CO2 surrounded by a porous shell of Al2O3 which supported a Ni catalyst. The best results were achi...

Nickel(0)-catalyzed cross-coupling of heteroaryl-containing diarylmethanes with both aryl bromides and chlorides has been achieved. The success of this reaction relies on the introduction of a unique nickel/NIXANTPHOS-based catalyst system, which provides a direct route to triarylmethanes from heteroaryl-containing diarylmethanes. Reactivity studies indicate the Ni(NIXANTPHOS)-based catalyst ex...