Silicon microreactors with thin-film wall catalyst were adopted for kinetic studies of CO preferential oxidation (PrOx). The activity of this catalyst was compared to other catalyst systems based on similar formulation. Internal and external mass transport and heat transport limitations of the microreactor were examined and comparisons were made to typical packed-bed lab reactors (m-PBR's). We ...

Aiming at an improved mechanistic understanding of the preferential oxidation of CO on supported Au catalysts, we have investigated the competition between CO and H2 for stable, active oxygen (Oact) species on a Au/TiO2 catalyst during the simultaneous exposure to CO and H2 with various CO/H2 ratios at 80 ̋C and 400 ̋C by quantitative temporal analysis of products (TAP) reactor measurements. It...

Industrial hydrogen production through methane steam reforming exceeds 50 million tons annually and accounts for 2-5% of global energy consumption. The hydrogen product, even after processing by the water-gas shift, still typically contains ∼1% CO, which must be removed for many applications. Methanation (CO + 3H2 → CH4 + H2O) is an effective solution to this problem, but consumes 5-15% of the ...

Hydrogen based proton exchange membranes (PEM) fuel cells show good potential for production of electricity. However, widespread commercialization of PEM fuel cells will depend on cheap and environmentally benign production of hydrogen. Currently, hydrogen is mainly produced from syngas by the water-gas shift (WGS) reaction (CO+H2O↔CO2+H2) followed by preferential oxidation (PROX) of CO. Extens...

Preferential oxidation (PROX) of CO is the most efficient way to remove CO from reformate streams for PEM fuel cells. Pt/Al2O3 has long been used for this purpose. Pt/Al2O3 catalysts are effective for preferential oxidation of CO only at temperatures above 150°C, and the maximum CO conversion usually takes place at around 200°C. In this study, promotion of Pt/Al2O3 with transition metals result...

Our recent studies of CO preferential oxidation (PrOx) identified systemic differences between the characteristic curves of CO conversion for a microchannel reactor with thin-film wall catalyst and conventional packed-bed lab reactors (m-PBR’s). Strong evidence has suggested that the reverse water-gas-shift (r-WGS) side reaction activated by temperature gradients in m-PBR’s is the source of the...

The hydrogen sorption properties of oxide-supported Ir-Pd nanoalloys have been determined for the first time, and correlated with their catalytic behavior. The addition of Ir to Pd suppresses hydride formation and leads to improved catalytic performances with respect to pure metals in the preferential oxidation of CO in H2 excess (PROX).

The human neurofilament (H) promoter contains multiple binding sites for nuclear proteins including a Proximal (Prox) site centered around the sequence GGTTGGACC and an adjacent pyrimidine (Pyr) tract site centered around the sequence CCCTCCTCCCC. Surprisingly binding to a probe containing the Prox/Pyr region of the NF(H) promoter was competed in gel shifts by an oligonucleotide containing only...