Herein we describe a combined experimental and computational study of electrochemical glycerol oxidation in acidic media on Pt(111) and Pt(100) electrodes. Our results show that glycerol oxidation is a very structure-sensitive reaction in terms of activity and, more surprisingly, in terms of selectivity. Using a combination of online HPLC and online electrochemical mass spectrometry, we show that on the Pt(111) electrode, glyceraldehyde, glyceric acid, and dihydroxyacetone are products of glycerol oxidation, while on the Pt(100) electrode, only glyceraldehyde was detected as the main product of the reaction. Density functional theory calculations show that this difference in selectivity is explained by different binding modes of dehydrogenated glycerol to the two surfaces. On Pt(111), the dehydrogenated glycerol intermediate binds to the surface through two single Pt–C bonds, yielding an enediol-like intermediate, which serves as a precursor to both glyceraldehyde and dihydroxyacetone. On Pt(100), the dehydrogenated glycerol intermediate binds to the surface through one double PtC bond, yielding glyceraldehyde as the only product. Stripping and in situ FTIR measurements show that CO is not the only strongly bound adsorbed intermediate of the oxidation of glycerol, glyceraldehyde, and dihydroxyacetone. Although the nature of this adsorbate is still unclear, this intermediate is highly resistant to oxidation and can only be removed from the Pt surface after multiple scans.

The oxygen evolution reaction (OER) and chlorine evolution reaction (CER) are electrochemical processes with high relevance to water splitting for (solar) energy conversion and industrial production of commodity chemicals, respectively. Carrying out the two reactions separately is challenging, since the catalytic intermediates are linked by scaling relations. Optimizing the efficiency of OER over CER in acidic media has proven especially difficult. In this regard, we have investigated the OER versus CER selectivity of manganese oxide (MnOx), a known OER catalyst. Thin films (∼5–20 nm) of MnOx were electrodeposited on glassy carbon-supported hydrous iridium oxide (IrOx/GC) in aqueous chloride solutions of pH ∼0.9. Using rotating ring–disk electrode voltammetry and online electrochemical mass spectrometry, it was found that deposition of MnOx onto IrOx decreases the CER selectivity of the system in the presence of 30 mM Cl– from 86% to less than 7%, making it a highly OER-selective catalyst. Detailed studies of the CER mechanism and ex-situ structure studies using SEM, TEM, and XPS suggest that the MnOx film is in fact not a catalytically active phase, but functions as a permeable overlayer that disfavors the transport of chloride ions.

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The electrochemical chlorine evolution reaction (CER) and oxygen evolution reaction (OER) represent core processes in the production of chlorine, relevant to bulk chemical manufacturing, and water splitting, the most promising technology for renewable energy storage. Unfortunately, because of an apparent coupling between their key binding intermediates, the two reactions can easily occur simultaneously, which is never an attractive outcome. In this work, using a series of iridium-based double perovskites and rotating ringdisk voltammetry to deconvolute parallel OER and CER currents, we explored the interdependence of CER and OER in dilute acidic chloride solutions of up to 120 mM, where both reactions may occur in parallel with similar current densities. We also employed online inductively coupled plasma-mass spectrometry (ICP-MS) measurements to probe the material stability and its dependence on chloride concentration. For all studied materials, we found a strong linear correlation between CER and OER activity as well as a comparable selectivity, strengthening the suggestion that OER and CER follow a scaling relationship. It was also found that chloride selectively enhances the dissolution of the noble metal component. A reaction order analysis was performed to gain insight into the CER mechanism, the effect of surface area changes due to adventitious leaching, and the observed suppressing effect of chloride on OER.

Circular double-stranded replication intermediates were identified in low-molecular-weight DNA of cells of the avian leukemia virus-induced lymphoblastoid cell line 1104-X-5 infected with chicken anemia virus (CAV). To characterize the genome of CAV, we cloned linearized CAV DNA into the vector pIC20H. Transfection of the circularized cloned insert into chicken cell lines caused a cytopathogenic effect, which was arrested when a chicken serum with neutralizing antibodies directed against CAV was added. Chickens inoculated at 1 day of age with CAV collected from cell lines transfected with cloned CAV DNA developed clinical signs of CAV. The 2,319-bp cloned CAV DNA contained all the genetic information needed for the complete replication cycle of CAV. The CAV DNA sequence has three partially overlapping major reading frames coding for putative peptides of 51.6, 24.0, and 13.6 kDa. The CAV genome probably contains only one promoter region and only one poly(A) addition signal. Southern blot analysis using oligomers derived from the CAV DNA sequence showed that infected cells contained doubleand single-stranded CAV DNAs, whereas purified virus contained only the minus strand. It is the first time that the genome of one of the three known single-stranded circular DNA viruses has been completely analyzed.