The local pH on electrode surfaces is known to play an important role in the electrochemical reduction of CO 2 , which could alter the chemical kinetics and molecular transport under the reaction conditions. Here we report the study of local pH effect on the catalytic performance of high-surface-area Cu electrocatalysts. The electroreduction of CO 2 was systematically investigated on three types of Cu nanowires with distinct surface roughness factors and nanostructures. The measured electrocatalytic activities and selectivities were further correlated to the simulated local pH on the electrode surface. It was revealed that the high local pH induced by the production of hydroxide from the reaction beneficially suppresses the evolution of hydrogen and enhances the selectivity toward multi-carbon products, but detrimentally limits the transport of CO 2 molecules at large current densities. An optimal range of local pH is determined for the electroreduction of CO 2 , which is insightful for improving the design of electrodes for more efficient energy conversion and chemical transformations.

Mass transfer effects play an important role in CO2 electroreduction, giving rise to diffusion-limited activity and selectivity on Cu nanowire electrocatalysts.

Ethanol represents a promising liquid energy source for fuel cells. The development of direct ethanol fuel cells (DEFCs) is however challenged by the lack of efficient electrocatalysts for the complete oxidation of ethanol to CO 2 . Here we report the investigation of ethanol electro-oxidation on monodisperse and homogeneous Pt 3 Sn alloy nanoparticles. Electrochemical studies were conducted comparatively on the Pt 3 Sn nanoparticles supported on carbon (Pt 3 Sn/C), a commercial Pt/C catalyst, as well as KOH-treated Pt 3 Sn/C with the surface tin species removed. Our studies reveal the dual role of Sn in the EOR electrocatalysis on Pt 3 Sn/C: the surface Sn, likely in the form of tin oxides, enhances the oxidation of *CH x intermediate to *CO; the subsurface metallic Sn weakens the binding of *CO and facilitates its oxidative removal. A synergy of these two roles, plus the presence of Pt surface sites capable of cleaving the C−C bond, gives rise to the enhanced complete oxidation of ethanol.

1,3,5-Trisacetoacetamidobenzene with three 1,3-diketo groups was synthesized by the reaction of 1,3,5-triaminobenzene with diketene. Discotic hydrazone compounds were prepared by the diazo coupling reaction between 1,3,5-trisacetoacetamidobenzene and diazonium salts of 4-alkyloxyphenylamines. The compounds existed in hydrazone forms exclusively, being stabilized by the intramolecular hydrogen bonds, and showed discotic nematic or columnar hexagonal mesophases.Discotic liquid crystals are of great interest because of both their unique self-assembled structures and their potential applications in devices such as photovoltaic solar cells 1 and electroluminescent displays. 2 To induce the formation of discotic liquid crystalline phases, rigidity and planarity in the central part of the mesogenic molecule are essential. Typical discotic liquid crystalline compounds comprise aromatic rings such as benzene, 3 triphenylene, 4 and truxene 5 as core and peripheral alkyl chains. In recent years, disklike assemblies of molecules other than discotic ones have been studied considerably in an attempt to develop new types of core architecture. The driving forces for the self-assembly of a nondiscotic molecule to form a disklike structure include hydrogen-bonding, 6-13 charge-transfer, [14][15][16] and ionic interactions. 17,18 Special attention has been given to intramolecular