No abstract

Methane is an abundant resource and the main constituent of natural gas. It can be converted into higher value-added products and as a subproduct of electricity co-generation. The application of polymer electrolyte reactors for the partial oxidation of methane to methanol to co-generate power and chemical products is a topic of great interest for gas and petroleum industries, especially with the use of materials with a lower amount of metals, such as palladium complex. In this study, we investigate the ideal relationship between cis -[6-(pyridin-2-yl)-1,3,5-triazine-2,4-diamine(dichloride)palladium(II)] (Pd-complex) nanostructure and carbon to obtain a stable, conductive, and functional reagent diffusion electrode. The physical and structural properties of the material were analyzed by Fourier transform infrared (FT-IR) and Raman spectroscopies, transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) techniques. The electrocatalytic activity studies revealed that the most active proportion was 20% of Pd-complex supported on carbon (m/m), which was measured with lower values of open-circuit and power density but with higher efficiency in methanol production with reaction rates of r = 4.2 mol L –1 ·h –1 at 0.05 V.

Carbon dioxide (CO2) is an important trace gas in Earth’s atmosphere. Its high concentration in the environment causes serious problems. Thus, it has become imperative to develop efficient ways to reduce CO2. One of the best strategies to transform this greenhouse gas is the use of solar energy for the photochemical reduction of CO2. However, this process is challenging due to a number of drawbacks that should be overcome for it to become a promising alternative for generation of sustainable fuels and chemicals. In this work, we have engineered molecular photocatalysts based on 2,6-(Pyridin-2-yl)-1,3,5-triazine-2,4-diamine 1 which mimic [2,2′;6′,2′′]­terpyridine (tpy) and its related complexes by coordination with transition metal ions. Because of the functional groups (-NH2 group) and the electronic structural modification of 1 as compared with tpy, remarkable photocatalytic properties over the CO2 reduction to CO were found for the free and metal ligands with turnover numbers (TONs) between 80–102 with BIH and 480–1370 with BID. An integrated method using structural characterization by X-ray diffraction analysis, experimental and density functional theory calculations was used to track the mechanistic pathways of the photocatalytic CO2 reduction reaction.