Bifunctionality is a key feature of many industrial catalysts, supported metal clusters and particles in particular, and the development of such catalysts for the CO 2 reduction reaction (CO 2 RR) to hydrocarbons and alcohols is gaining traction in light of recent advancements in the field. Carbonsupported Cu nanoparticles are suitable candidates for integration in the state-ofthe-art reaction interfaces, and here, we propose, synthesize, and evaluate a bifunctional Ni−N-doped-C-supported Cu electrocatalyst, in which the support possesses active sites for selective CO 2 conversion to CO and Cu nanoparticles catalyze either the direct CO 2 or CO reduction to hydrocarbons. In this work, we introduce the scientific rationale behind the concept, its applicability, and the challenges with regard to the catalyst. From the practical aspect, the deposition of Cu nanoparticles onto carbon black and Ni−N−C supports via an ammonia-driven deposition precipitation method is reported and explored in more detail using X-ray diffraction, thermogravimetric analysis, and hydrogen temperature-programmed reduction. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectroscopy (EDXS) give further evidence of the presence of Cu-containing nanoparticles on the Ni−N−C supports while revealing an additional relationship between the nanoparticle's composition and the electrode's electrocatalytic performance. Compared to the benchmark carbon black-supported Cu catalysts, Ni−N−C-supported Cu delivers up to a 2-fold increase in the partial C 2 H 4 current density at −1.05 V RHE (C 1 /C 2 = 0.67) and a concomitant 10-fold increase of the CO partial current density. The enhanced ethylene production metrics, obtained by virtue of the higher intrinsic activity of the Ni−N−C support, point out toward a synergistic action between the two catalytic functionalities.

Mixed oxides were synthesized by co-precipitation of a Cu source in combination with Al, Fe or Mn corresponding salts as precursors. The materials were calcined at 600 and 1000 °C in order to crystallize the phases and to mimic the reaction conditions of the catalytic application. At 600 °C a mixed spinel structure was only formed for the combination of Cu and Mn, while at 1000 °C all the materials showed mixed spinel formation. The catalysts were applied in three-way catalysis using a reactor with a gas mixture containing CO, NO and O2. All the materials calcined at 600 °C displayed the remarkable ability to oxidize CO with O2 but also to reduce NO with CO, while the pure oxides such as CuO and MnO2 were not able to. The high catalytic activity at 600 °C was attributed to small supported CuO particles present and imperfections in the spinel structure. Calcination at 1000 °C crystallized the structure further which led to a dramatic loss in catalytic activity, although CuAl2O4 and CuFe2O4 still converted some NO. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, H2-Temperatrue Programmed Reduction (H2-TPR), N2-sorption and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX).

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This study is part of an anti-corrosion coating development project at CHEMSYSTEMS. The corrosion performance was assessed through erosion, immersion and soil corrosion experiments. The erosion results have previously been published. This article discusses the impact of soil on control polyaspartic coatings used to protect concrete and the modified polyaspartic coating intended to protect underground steel substrates. The modified polyaspartic coating was boosted with a micaceous iron oxide barrier, a liquid alkylammonium corrosion inhibitor, a powdered zinc phosphate corrosion inhibitor and a novel hardener. The surface finish of the steel samples was of a milled and blasted nature (SA 2.5). The coating was applied directly to the metal without the application of a primer or second layer of coating. The average thickness of the coating was 220±10 µm as a direct-to-metal protection system. The experiments were conducted in soil at room temperature (RT) and 35°C over 30 days. The experimental results of the control polyaspartic coating loaded on steel substrates exhibited severe blistering. The polyaspartic coating dispersed with a liquid alkylammonium inhibitor also exhibited blistering, whereas the modified polyaspartic coating with a zinc phosphate corrosion inhibitor showed an adequate degree of resistance to the impact of soil under the evaluated conditions. The results confirmed that the presence of a zinc phosphate corrosion inhibitor in combination with a micaceous iron oxide barrier improved the resistance of the coating to the evaluated soils in which it was positioned and at the investigated temperatures.