Showing papers by "Sebastian C. Peter published in 2023"
TL;DR: In this article , a chemically stable, pyridine-equipped, and imine-linked porous organic polymer (Py-POP) was constructed by template-free Schiff base condensation of 1,3,5-tris(4-aminophenyl) benzene (APB) and 2,6-pyridinedicarboxaldehyde (PDC).
Abstract: Porous organic polymers (POPs) continue to garner immense attention for CO2 capture and sequestration (CCS) as well as CO2 fixation to generate useful chemicals for alleviating global warming. Functionally engineered, visible light responsive organic photopolymers with extended π-conjugation and abundant heteroatoms enable photogenerated charge carriers, enhancement in visible light absorption, higher charge separation, and reduction in charge recombination during photocatalysis. In this work, we have explored the construction of a chemically stable, pyridine-equipped, and imine-linked porous organic polymer (Py-POP) by template-free Schiff base condensation of 1,3,5-tris(4-aminophenyl) benzene (APB) and 2,6-pyridinedicarboxaldehyde (PDC). This donor–acceptor Py-POP with extensive π-conjugations enables photocatalytic fixation of CO2 with styrene epoxide (STE) under visible light illumination. We have achieved an impressive conversion of STE to styrene carbonate (STC) (∼99%) under optimized reaction conditions using tert-butyl ammonium bromide (TBAB) as a promoter. Both the efficient CO2 adsorption and activation for photocatalytic fixation reaction are enabled by the existence of both imine and pyridine moieties in Py-POP. The interaction between Py-POP and CO2 is further illustrated by density functional theory (DFT) calculations that show that all the POP-CO2 interactions are favorable and exergonic. Using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) characterization techniques, we elucidate the mechanistic pathways of active key surface species in CO2 photofixation with Py-POP. Our results provide mechanistic insight into the effectiveness of efficient, sustainable porous organic photocatalysts in visible light-driven CO2 conversion for various energy applications.
3 citations
TL;DR: In this paper , the chemical stability in correlation to Hydrogen peroxide (H2O2) of a two-step modified stainless steel surface was studied, where the surface was nanostructured by means of ultrashort pulse lasers and then the laser-treated surface was chemically modified by a self-assembled monolayer (SAM).
TL;DR: In this paper , a low Pt containing ZnO (PZ) is prepared by a simultaneous borohydride reduction and PZ is then loaded onto Vulcan carbon to produce a very low Pt content electrocatalyst, PZ@VC.
Abstract: The development of robust electrocatalysts with low platinum content for acidic hydrogen evolution reaction (HER) is paramount for large scale commercialization of proton exchange membrane electrolyzers. Herein, a simple strategy is reported to synthesize a well anchored, low Pt containing Vulcan carbon catalyst using ZnO as a sacrificial template. Pt containing ZnO (PZ) is prepared by a simultaneous borohydride reduction. PZ is then loaded onto Vulcan carbon to produce a very low Pt content electrocatalyst, PZ@VC. PZ@VC with 2 wt.% Pt shows excellent performance for acidic HER in comparison to the commercial Pt/C (20 wt.%) catalyst. PZ@VC with a very low Pt loading shows significantly low η10 and η100 values (15 and 46 mV, respectively). PZ@VC on coating with Nafion (PZ@VC-N) shows further improvement in its performance (η10 of 7 mV, η100 of 28 mV) with ≈300 h of stability (≈10 mA cm-2 ) with only 4 µgPt cm-2 . PZ@VC-N shows a record high mass activity of 71 A mgPt -1 (32 times larger than Pt/C (20 wt.%) at 50 mV of overpotential. Post reaction characterizations reveal Pt nanoparticles are embedded onto VC with no traces of zinc, suggestive of a strong metal-support interaction leading to this high stability at low Pt loading.