Nitrogen-containing carbon nanotubes (NCNTs) were prepared via pyrolysis of acetonitrile over cobalt catalysts at different temperatures to control the nitrogen content. The changes in the chemical and structural properties of undoped CNTs and NCNTs were investigated using high-resolution X-ray photoelectron and Raman spectroscopy. The NCNTs prepared at 550°C had a higher amount of pyridinic groups and edge plane exposure than the ones prepared at 750°C. The thermal stability and transformation of these nitrogen functional groups was studied using deconvoluted XP N 1s spectra. The NCNTs show a considerably higher activity in the oxygen reduction reaction in acidic electrolyte compared with undoped CNTs as demonstrated by cyclic voltammetry, rotating disk electrode measurements, and the redox-competition mode of scanning electrochemical microscopy (RC-SECM). Particularly, the NCNT sample prepared at 550°C exhibited the highest activity, which was about 1 order of magnitude lower than that of a commercial Pt/C sample containing 20 wt % Pt. The oxygen reduction reaction (ORR) performance of this sample showed hardly any signs of deterioration after 3 days, as determined by voltammetric stability tests in H 2 SO 4 .

Steel substrates were coated with a water-borne epoxy polymer layer and investigated by in situ scanning Kelvin probe ͑SKP͒ experiments, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, and peel tests. After ion transport processes along the polymer/substrate interface were initialized at an electrolyte covered coating defect, nonspecific potential profiles were detected with the SKP. An identification of the front position of the electrolyte was not possible in air of high relative humidity, because wet de-adhesion and hydrolysis processes determined the local interface potential. Although the established mechanistic model for cathodic delamination solely predicts a cation transport in humid air, anions of the defect electrolyte were also verifiable at the epoxy/steel interface. It is discussed which forces rather than ion diffusion were additionally effective and contributed to the overall driving forces for the ion transport in this case. The oxidation state of the resulting substrate structure was investigated to further analyze the epoxy/steel interface degradation. These results are compared to the initial surface condition of the uncoated steel surface. They are also compared to the surface condition after oxygen reduction induced electrolyte spreading proceeded along the uncoated steel substrate.

A new class of viscoelastic surfactants for chemical enhanced oil recovery is presented. The triphenoxmethanes (TPM) show promise under harsh conditions of high salinity and high temperatures. The TPM's are viscoelastic at low concentrations (<0.5%w/w), show good stability in highly saline brine (18.6% TDS) that contains high concentrations of divalent cations at elevated temperatures (>70°C). Static adsorption measurements show acceptable values for the harsh conditions under study. Rheological measurements demonstrate that the viscoelasticity is not from formation of wormlike micelles and displays non-Maxwell behavior. We propose a novel supramolecular structure that explains the laboratory and rheological observations to date. The compounds show good injectivity into 2 Darcy Gildehaus sandstone The development of this class of compounds combines the efforts of a team comprised of synthesis, analytics, rheology, core lab and computational chemistry. The goal is to develop an understanding the system's behavior from the molecular level in-silico via computational chemistry, through coreflood tests -and beyond- for a future field pilot. The structure- property-relationships that are being developed will lead to further refinement and targeted development of next generation molecules with improved properties.