First-principles modeling of the polycyclic aromatic hydrocarbons reduction

Density functional theory modelling of the reduction of realistic nanographene molecules (C42H18, C48H18 and C60H24) by molecular hydrogen evidences for the presence of limits in the hydrogenation process. These limits caused the contentions between three-fold symmetry of polycyclic aromatic hydrocarbon molecules and two-fold symmetry of adsorbed hydrogen pairs. Increase of the binding energy between nanographenes during reduction is also discussed as possible cause of the experimentally observed limited hydrogenation of studied nanographenes.Comment: 18 pages, 7 figures, accepted to J. Phys. Chem.

Template-Assisted Mechanosynthesis Leading to Benchmark Energy Efficiency and Sustainability in the Production of Bifunctional Fe-N-C Electrocatalysts

Efficient and sustainable synthesis of performant metal/nitrogen-doped carbon (M-N-C) catalysts for oxygen reduction and evolution reactions (ORR/OER) is vital for the global switch to green energy technologies-fuel cells and metal-air batteries. This study reports a solid-phase template-assisted mechanosynthesis of Fe-N-C, featuring low-cost and sustainable FeCl3, 2,4,6-tri(2-pyridyl)-1,3,5-triazine (TPTZ), and NaCl. A NaCl-templated Fe-TPTZ metal-organic material was formed using facile liquid-assisted grinding/compression. With NaCl, the Fe-TPTZ template-induced stability allows for a rapid, thus, energy-efficient pyrolysis. Among the produced materials, 3D-FeNC-LAG exhibits remarkable performance in ORR (E1/2 = 0.85 V and Eonset = 1.00 V), OER (Ej=10 = 1.73 V), and in the zinc-air battery test (power density of 139 mW cm-2). The multilayer stream mapping (MSM) framework is presented as a tool for creating a sustainability assessment protocol for the catalyst production process. MSM employs time, cost, resource, and energy efficiency as technoeconomic sustainability metrics to assess the potential upstream impact. MSM analysis shows that the 3D-FeNC-LAG synthesis exhibits 90% overall process efficiency and 97.67% cost efficiency. The proposed synthetic protocol requires 2 times less processing time and 3 times less energy without compromising the catalyst efficiency, superior to the most advanced methods.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Team Peyman Taher

Template-Assisted Mechanosynthesis Leading to Benchmark Energy Efficiency and Sustainability in the Production of Bifunctional Fe-N-C Electrocatalysts

Efficient and sustainable synthesis of performant metal/nitrogen-doped carbon (M-N-C) catalysts for oxygen reduction and evolution reactions (ORR/OER) is vital for the global switch to green energy technologies-fuel cells and metal-air batteries. This study reports a solid-phase template-assisted mechanosynthesis of Fe-N-C, featuring low-cost and sustainable FeCl3, 2,4,6-tri(2-pyridyl)-1,3,5-triazine (TPTZ), and NaCl. A NaCl-templated Fe-TPTZ metal-organic material was formed using facile liquid-assisted grinding/compression. With NaCl, the Fe-TPTZ template-induced stability allows for a rapid, thus, energy-efficient pyrolysis. Among the produced materials, 3D-FeNC-LAG exhibits remarkable performance in ORR (E1/2 = 0.85 V and Eonset = 1.00 V), OER (Ej=10 = 1.73 V), and in the zinc-air battery test (power density of 139 mW cm-2). The multilayer stream mapping (MSM) framework is presented as a tool for creating a sustainability assessment protocol for the catalyst production process. MSM employs time, cost, resource, and energy efficiency as technoeconomic sustainability metrics to assess the potential upstream impact. MSM analysis shows that the 3D-FeNC-LAG synthesis exhibits 90% overall process efficiency and 97.67% cost efficiency. The proposed synthetic protocol requires 2 times less processing time and 3 times less energy without compromising the catalyst efficiency, superior to the most advanced methods.</p

The Study on the Medium-Sized Carbon Islands on Ru(0001) Surface

During chemical vapor deposition (CVD) growth of graphene on Ru(0001) surface, a specific C cluster, which has 13 C atoms arranged as three connected hexagons (so called 3-C-6), was supposed to be extremely stable. To verify this, we systemically explored the stabilities of carbon clusters C-N (N = 12, 13, 14) on the Ru(0001) surface by using first principle approach. While, it is surprising that neither 3-C-6 is the ground state of C-13 nor the C-13 cluster shows exceptional stability. So, based on the experimental STM image with C-3v symmetry and a dimmer of 1 nm, the magic cluster was proposed as C-21 or C-21-3C, which have the same core composed of six hexagons and three pentagons, as that studied before. This study is helpful to resolve the debate on the dominating clusters observed during graphene CVD growth and is helpful for understanding the growth mechanism of graphene CVD growth