An ultra-high vacuum experimental study of acetylene chemisorption on Pt(111) and Pt(100) and of the reaction of hydrogen with the acetylene adsorbate has established distinguishing features of carbon-hydrogen bond breaking and making processes as a function of pressure, temperature, and surface crystallography. The rates for both processes are substantially higher on the Pt(100) surface. Net a...

The effect of composition and morphology of bimetallic Pd-Au nanoclusters on their chemical reactivity has been studied with acetylene decomposition and conversion to ethylene and benzene as the chemical probe. High resolution transmission electron microscopy (HR-TEM) and CO-Temperature Programmed Desorption (TPD) measurements were employed for structure and chemical composition determination. ...

The structurally well-defined intermetallic compounds PdGa and Pd3Ga7 constitute suitable catalysts for the selective hydrogenation of acetylene. The surface properties of PdGa and Pd3Ga7 were characterized by X-ray photoelectron spectroscopy, ion scattering spectroscopy and CO chemisorption. Catalytic activity, selectivity and long-term stability of PdGa and Pd3Ga7 were investigated under diff...

A novel TiO2 supported core-shell (Pd@Ag) bimetallic catalyst was fabricated via the sequential photodeposition method. The Ag shell effectively blocks the high coordination sites on the Pd core, and therefore pronouncedly enhances the ethylene selectivity for the catalytic hydrogenation of acetylene in excess ethylene.

The rational design of metal-organic frameworks (MOFs) with hollow features and tunable porosity at the nanoscale can enhance their intrinsic properties and stimulates increasing attentions. In this Communication, we demonstrate that methanol can affect the coordination mode of ZIF-67 in the presence of Co(2+) and induces a mild phase transformation under solvothermal conditions. By applying th...

in this study simulation and optimization of an industrial acetylene hydrogenation reactor was studied. three well known kinetic models were used for a nearly similar catalyst to predict the industrial data. due to the complexity of the reactions, none of the offered kinetic models could be considered as an exact kinetic model and it is necessary to determine the kinetic parameters. one of the ...

The stabilities and catalytic performances of single-atom alloy (SAA) structures under the reaction conditions of acetylene hydrogenation are thoroughly examined utilizing density functional theory (DFT) calculations. Four Cu-based alloys with stable SAA structures reported before, namely PdCu, PtCu, RhCu and NiCu alloys, are investigated here. We find that the SAA structures of PdCu and PtCu a...

Adsorption and co-adsorption of ethylene, acetylene and hydrogen on Pd-Ag particles, supported on thin alumina films, have been studied by temperature programmed desorption (TPD). The TPD results show that adding of Ag to Pd suppresses overall hydrogenat ion activity but increases selectivity towards ethylene, i.e. similar to that observed on real catalysts. The results are rationalized on the ...

Palladium dynamics: Under hydrogenation conditions, saturating over-active palladium by carbon diffusion leads to a stable and selective particle surface. By choosing supports with suitable geometric structures and establishing a strong interaction between supports and metal particles, accumulated species can be regularly rearranged and reaction-selective phases can be exposed (see figure).

The structure sensitivity of Pd catalysed acetylene hydrogenation is quantitatively examined using a coverage-dependent microkinetic model. Pd(211) was found to be more active than Pd(111), but present poorer selectivity toward ethylene.