Gilmore Jacobsen (banjopeen11)

Density functional theory (DFT) has been considered as a powerful tool for the identification of reaction mechanisms. However, it is still unclear whether the error of DFT calculations would lead to mis-identification of mechanisms. Here, taking the hydrogenation of acetylene and 1,3-butadiene as model reactions and employing a well-trained Bayesian error estimation functional with van der Waals correlation (BEEF-vdW), we try to estimate the error of DFT calculation results statistically, and therefore predict the reliability of the hydrogenation mechanisms identified. With an ensemble of 2000 functionals obtained around the BEEF-vdW functional as well as a descriptor developed to represent the possibility of different mechanisms, we found that the non-Horiuti-Polanyi mechanism is preferred on Ag(211) and Au(211), while the Horiuti-Polanyi mechanism is dominant on Cu(211). We further discovered that the descriptor is linearly correlated with the adsorption energies of reaction intermediates during acetylene and butadiene hydrogenation, and the hydrogenation of strongly adsorbed species are more likely to follow the Horiuti-Polanyi mechanism. We found the probability of following the non-HP mechanism obeys the order Cu(211) less then Au(211) less then Ag(211). Our work gives a more comprehensive explanation for the mechanisms of coinage metal catalyzed hydrogenation reactions, and also provides more theoretical insights into the development of new high-performance catalysts for selective hydrogenation reactions.In this work, we report the first exploration of cathodic photoelectrochemistry for the determination of the activity of DNA adenine methylation (Dam) methyltransferase (MTase). In this sensing system, potassium ferricyanide (K3[Fe(CN)6]) can greatly stimulate the photocurrent of a CdS quantum dot (QD) sensitized NiO (NiO/CdS) photocathode. After immobilization of the hairpin DNA probe on the electrode surface, its high steric hindrance and the electrostatic repulsion block the access of K3[Fe(CN)6] to the electrode surface, leading to depressed photocurrent of the photocathode. Once the hairpin DNA probe is methylated by Dam MTase, it can be recognized and cleaved by Dpn I, and then further digested by (Exo I), ultimately leading to the removal of the hairpin DNA probe from the electrode surface. Palbociclib nmr This configurational change induces the decrement of steric hindrance/electrostatic repulsion effects and allows the efficient flux of K3[Fe(CN)6] to the photoelectrode for photocurrent stimulation. The cathodic PEC assay is presented in the "turn-on" mode, which can detect Dam MTase in the linear range from 0.04 to 100 U mL-1, with a detection limit as low as 0.028 U mL-1. In principle, the platform presents a promising method for probing various biomolecules that can lead to configuration or charge variations at the electrode surface, which may become a general strategy for versatile targets.In this study, the process economics of ammonia synthesis over Co3Mo3N was investigated by searching for an optimum feed stoichiometry. From ammonia synthesis rate measurements at atmospheric pressure and 400 °C over Co3Mo3N, it was found that the rate was independent of H2 N2 stoichiometry for stoichiometries above 0.5 1. For H2 N2 stoichiometries below 0.5 1, there was a linear dependency of ammonia synthesis rate on the H2 N2 stoichiometry. Static measurements of hydrogen adsorption isotherms at 25, 50, and 100 °C revealed that the adsorbed amounts of strongly bound hydrogen over the Co3Mo3N surface were saturated at around 100 Torr hydrogen pressure. This pressure corresponds to the partial pressure of hydrogen when the H2 N2 stoichiometry is around 0.5 1, confirming the role of strongly bound hydrogen in ammonia synthesis. These results were used to modify an existing kinetic expression to be used in a conceptual design, based on a late mixing strategy for the hydrogen stream. This conceptual design and its