Angelika Brückner

Abstract: Solar hydrogen production from water could be a sustainable and environmentally friendly alternative to fossil energy carriers, yet so far photocatalysts active and stable enough for large-scale applications are not available, calling for advanced research efforts. In this work, H2 evolution rates of up to 1968 and 5188 μmol h−1 g−1 were obtained from aqueous solutions of triethanolamine (TEOA) and oxalic acid (OA), respectively, by irradiating composites of AgIn5S8 (AIS), mesoporous C3N4 (CN, surface area >150 m2/g) and ≤2 wt.% in-situ photodeposited Pt nanoparticles (NPs) with UV-vis (≥300 nm) and pure visible light (≥420 nm). Structural properties and electron transport in these materials were analyzed by XRD, STEM-HAADF, XPS, UV-vis-DRS, ATR-IR, photoluminescence and in situ-EPR spectroscopy. Initial H2 formation rates were highest for Pt/CN, yet with TEOA this catalyst deactivated by inclusion of Pt NPs in the matrix of CN (most pronounced at λ ≥ 300 nm) while it remained active with OA, since in this case Pt NPs were enriched on the outermost surface of CN. In Pt/AIS-CN catalysts, Pt NPs were preferentially deposited on the surface of the AIS phase which prevents them from inclusion in the CN phase but reduces simultaneously the initial H2 evolution rate. This suggests that AIS hinders transport of separated electrons from the CN conduction band to Pt NPs but retains the latter accessible by protons to produce H2.

TL;DR: An accelerated deactivation procedure for a commercial Ag-based catalyst for ethylene epoxidation was developed in a gradientless Berty-recycle reactor by increasing temperature and oxygen concentration which, however, were kept constant in the whole reactor for a single experiment.

TL;DR: The conversion of sunlight into chemical energy is a very promising research topic, and the discovery of the Honda–Fujishima effect describes the photoassisted generation of dihydrogen and dioxygen from water using a TiO2/Pt electrode array.

TL;DR: In this article, a mesoporous Al2O3, SBA-15 and MCM-48 materials have been studied by simultaneous in situ-EPR/UV-vis/on line GC measurements and tested as catalysts for the ODH of propane.