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Many Cu alloys have been studied for electrocatalytic activity of CO2 reduction in 0.05M KHCO~ aqueous solution. Anomalously low overpotentials with highly selective Cu alloy catalysts have been seen for the reduction of CO2 to CH3OH, HCOOH, or CO. Cu-Ni alloys produce CH3OH and HCOOH selectively at reversible potentials and Cu-Sn and Cu-Pb produce HCOOH and CO with an enhanced reaction rate at the reversible potentials of formation. Other alloy catalysts such as Cu-Zn, Cu-Cd, or Cu-Ag also exhibit behaviors distinct from those of the elemental metals. The results reported here indicate further possibilities for the development of powerful new electrocatalysts for the reduction of CO2.

Simultaneous reduction of carbon dioxide and nitrate ions was examined at gas-diffusion electrodes with various catalysts (Cr,

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Simultaneous reduction of carbon dioxide and nitrite ions was examined at the gas-diffusion electrodes with various catalysts (Cr,

New concepts for a high performance catalyzed-reaction layer for medium temperature operating solid oxide fuel cells were proposed. Mixed conducting oxide particles, samaria-doped ceria (SDC), were employed as the anode material utilizing highly dispersed noble metal catalysts on their surface. As the cathode material, Sr-doped LaMnO3 (LSM) particles catalyzed with microcrystalline Pt were employed. Performances of the anode or cathode were examined in the cell using yttria-stabilized zirconia electrolyte at a series of operating temperatures. It was found that the anodic polarization resistance and its activation energy were greatly decreased by loading only a small amount of the catalysts (such as Ru, Rh, and Pt) onto the SDC particles. The polarization loss at the anode showed a minimum value by using the SDC particles with a mean diameter of 1.5 to 2.0 ~m. A large depolarizing effect was also observed with a Pt-catalyzed LSM cathode, especially at high current densities.

Protein S-nitrosylation modulates important cellular processes, including neurotransmission, vasodilation, proliferation, and apoptosis in various cell types. We have previously reported that protein disulfide isomerase (PDI) is S-nitrosylated in brains of patients with sporadic neurodegenerative diseases. This modification inhibits PDI enzymatic activity and consequently leads to the accumulation of unfolded/misfolded proteins in the endoplasmic reticulum (ER) lumen. Here, we describe S-nitrosylation of additional ER pathways that affect the unfolded protein response (UPR) in cell-based models of Parkinson’s disease (PD). We demonstrate that nitric oxide (NO) can S-nitrosylate the ER stress sensors IRE1α and PERK. While S-nitrosylation of IRE1α inhibited its ribonuclease activity, S-nitrosylation of PERK activated its kinase activity and downstream phosphorylation/inactivation or eIF2α. Site-directed mutagenesis of IRE1α(Cys931) prevented S-nitrosylation and inhibition of its ribonuclease activity, indicating that Cys931 is the predominant site of S-nitrosylation. Importantly, cells overexpressing mutant IRE1α(C931S) were resistant to NO-induced damage. Our findings show that nitrosative stress leads to dysfunctional ER stress signaling, thus contributing to neuronal cell death.

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