An Investigation into Polyester Adsorption onto Alumina toward an Improved Understanding of Hydrogenolysis Catalysts.

Chemical recycling of end-of-life plastic wastes through hydrogenolysis is a promising pathway for achieving a circular plastics economy and reducing overall energy costs. Understanding molecular interactions at the inorganic-organic depolymerization interface is crucial for enhancing catalyst performance and overcoming challenges posed by mixed plastic waste streams. We investigated a fundamental step in the depolymerization process: physisorption of polymers onto the metal oxide support preceding diffusion to and reaction at the catalyst-support junction.

Enhancing the Self-Propelled Motion of Hydrogen Peroxide Fueled Active Particles with Formic Acid and Other Oxygen Scavengers.

We report enhanced active particle motion in hydrogen peroxide-fueled self-diffusiophoretic active particle systems of up to 400% via addition of low concentrations of oxygen scavenging agents such as formic acid (as well as other organic acids, hydrazine, and citric acid), whereas active motion was inhibited at higher concentrations. Control experiments showed that enhanced motion was decoupled from catalytic hydrogen peroxide decomposition rate and insensitive to particle surface chemistry. Experimental results point to bulk oxygen scavenging as the cause for the enhanced active motion, representing a realization of recently predicted promotional effects of product sinks on self-diffusiophoretic motion.

Design and Validation of a High-Throughput Reductive Catalytic Fractionation Method.

Reductive catalytic fractionation (RCF) is a promising method to extract and depolymerize lignin from biomass, and bench-scale studies have enabled considerable progress in the past decade. RCF experiments are typically conducted in pressurized batch reactors with volumes ranging between 50 and 1000 mL, limiting the throughput of these experiments to one to six reactions per day for an individual researcher. Here, we report a high-throughput RCF (HTP-RCF) method in which batch RCF reactions are conducted in 1 mL wells machined directly into Hastelloy reactor plates.

Electrochemical Stability of Thiolate Self-Assembled Monolayers on Au, Pt, and Cu.

Self-assembled monolayers (SAMs) of thiolates have increasingly been used for modification of metal surfaces in electrochemical applications including selective catalysis (e.g., CO reduction, nitrogen reduction) and chemical sensing.

Multiple Roles of Alkanethiolate-Ligands in Direct Formation of H O over Pd Nanoparticles.

Coadsorbed organic species including thiolates can promote direct synthesis of hydrogen peroxide from H and O over Pd particles. Here, density functional theory based kinetic modeling, augmented with activity measurements and vibrational spectroscopy are used to provide atomistic understanding of direct H O formation over alkylthiolate(RS) Pd. We find that the RS species are oxidized during reaction conditions yielding RSO as the effective ligand.

Effects of Surface Hydrophobicity on Catalytic Transfer Hydrogenation of Styrene with Formic Acid in a Biphasic Mixture.

Transfer hydrogenation (TH) of unsaturated hydrocarbons with formic acid (FA) is an attractive processing pathway for the reduction of lignocellulosic pyrolysis oils. The low solubility of hydrophobic bio-oil species in water and FA in oil necessitates the use of a biphasic system as the reaction environment. Here, we report the effects of Pd/silica catalyst surface wettability on the TH reaction rate.

Probing surface-adsorbate interactions through active particle dynamics.

Adsorbate molecules present in a reaction mixture may bind to and block catalytic sites. Measurement of the surface coverage of these molecules via adsorption isotherms is critical for modeling and design of catalytic reactions on surfaces. However, it is challenging to measure isotherms in solution in a way that is directly relevant to catalytic activity under reaction conditions, particularly since adsorbates may bind with an enormous range of surface affinity parameters.

Controlling Heterogeneous Catalysis with Organic Monolayers on Metal Oxides.

ConspectusA key theme of heterogeneous catalysis research is achieving control of the environment surrounding the active site to precisely steer the reactivity toward desired reaction products. One method toward this goal has been the use of organic ligands or self-assembled monolayers (SAMs) on metal nanoparticles. Metal-bound SAMs are typically employed to improve catalyst selectivity but often decrease the reaction rate as a result of site blocking from the ligands.

An experimental approach for controlling confinement effects at catalyst interfaces.

Catalysts are conventionally designed with a focus on enthalpic effects, manipulating the Arrhenius activation energy. This approach ignores the possibility of designing materials to control the entropic factors that determine the pre-exponential factor. Here we investigate a new method of designing supported Pt catalysts with varying degrees of molecular confinement at the active site.

Dexamethasone prodrug nanomedicine (ZSJ-0228) treatment significantly reduces lupus nephritis in mice without measurable side effects - A 5-month study.

Lupus nephritis (LN) is a major cause of morbidity and mortality among systemic lupus erythematosus patients. Glucocorticoids (GCs) are uniformly used in clinical LN management. Their notorious toxicities, however, have hampered the long-term clinical application.

Control of Molecular Bonding Strength on Metal Catalysts with Organic Monolayers for CO Reduction.

The development of separate levers for controlling the bonding strength of different reactive species on catalyst surfaces is challenging but essential for the design of highly active and selective catalysts. For example, during CO reduction, production of CO often requires balancing a trade-off between the adsorption strength of the reactant and product states: weak binding of CO is desirable from a selectivity perspective, but weak binding of CO leads to low activity. Here, we demonstrate a new method of controlling both CO adsorption and CO desorption over supported metal catalysts by employing a single self-assembly step where organic monolayer films were deposited on the catalyst support.

Molecular Determinants of Substrate Selectivity of a Pneumococcal Rgg-Regulated Peptidase-Containing ABC Transporter.

Peptidase-containing ABC transporters (PCATs) are a widely distributed family of transporters which secrete double-glycine (GG) peptides. In the opportunistic pathogen (pneumococcus), the PCATs ComAB and BlpAB have been shown to secrete quorum-sensing pheromones and bacteriocins related to the competence and pneumocin pathways. Here, we describe another pneumococcal PCAT, RtgAB, encoded by the locus and found intact in 17% of strains.

The Impact of the Chronic Disease Self-Management Program on Health Literacy: A Pre-Post Study Using a Multi-Dimensional Health Literacy Instrument.

This study assessed the impact of the Chronic Disease Self-Management Program (CDSMP) on different domains of health literacy using a pre-post study design. Participants aged over 16 years and with one or more self-reported chronic diseases were recruited for the CDSMP in western Sydney (a highly diverse area of New South Wales, Australia) between October 2014 and September 2018 Health literacy was assessed pre- and immediately post-intervention using the Health Literacy Questionnaire (HLQ), with differences in mean scores for each HLQ domain analysed using paired sample t-tests. A total of 486 participants were recruited into the CDSMP.

Controlling Catalyst-Phase Selectivity in Complex Mixtures with Amphiphilic Janus Particles.

Amphiphilic Janus particles with a catalyst selectively loaded on either the hydrophobic or hydrophilic region are promising candidates for efficient and phase-selective interfacial catalysis. Here, we report the synthesis and characterization of Janus silica particles with a hydrophilic silica domain and a silane-modified hydrophobic domain produced via a wax masking technique. Palladium nanoparticles were regioselectively deposited on the hydrophobic side, and the phase selectivity of the catalytic Janus particles was established through the kinetic studies of benzyl alcohol hydrodeoxygenation (HDO).

Enhancing Au/TiO Catalyst Thermostability and Coking Resistance with Alkyl Phosphonic-Acid Self-Assembled Monolayers.

Metal oxide-supported Au catalysts, particularly those with small Au nanoparticles, catalyze a variety of reactions including low-temperature CO oxidation and selective hydrogenation of alkynes. However, the facile nature of Au particle growth at even moderate temperatures poses significant challenges to maintaining catalyst activity under reaction conditions. Here, we present a method to reduce the rate of sintering and coke formation in TiO-supported Au catalysts via the deposition of alkyl-phosphonic acid (PA) self-assembled monolayers.

Thermodynamics of Alkanethiol Self-Assembled Monolayer Assembly on Pd Surfaces.

We investigate the structure and binding energy of alkanethiolate self-assembled monolayers (SAMs) on Pd (111), Pd (100), and Pd (110) facets at different coverages. Dispersion-corrected density functional theory calculations are used to correlate the binding energy of alkanethiolates with alkyl chain length and coverage. The equilibrium coverage of thiolate layers strongly prefers 1/3 monolayer (ML) on the Pd (111) surface.

Pulmonary manifestations in late versus early systemic lupus erythematosus: A systematic review and meta-analysis.

Objectives: Phenotypes differ between late- and early-onset systemic lupus erythematosus (SLE). Prior studies suggested that there may be more pulmonary disease among late-onset patients. Our objective was to perform a systematic review and meta-analysis to evaluate the differences in pulmonary manifestations in late- versus early-onset SLE.

Enhanced Hydrothermal Stability of γ-AlO Catalyst Supports with Alkyl Phosphonate Coatings.

In this study, monolayers formed from organophosphonic acids were employed to stabilize porous γ-AlO, both as a single component and as a support for Pt nanoparticle catalysts, during exposure to hydrothermal conditions. To provide a baseline, structural changes of uncoated γ-AlO catalysts under model aqueous phase reforming conditions (liquid water at 200 °C and autogenic pressure) were examined over the course of 20 h. These changes were characterized by X-ray diffraction, NMR spectroscopy, N physisorption, and IR spectroscopy.

Directing Reaction Pathways through Controlled Reactant Binding at Pd-TiO Interfaces.

Recent efforts to design selective catalysts for multi-step reactions, such as hydrodeoxygenation (HDO), have emphasized the preparation of active sites at the interface between two materials having different properties. However, achieving precise control over interfacial properties, and thus reaction selectivity, has remained a challenge. Here, we encapsulated Pd nanoparticles (NPs) with TiO films of regulated porosity to gain a new level of control over catalyst performance, resulting in essentially 100 % HDO selectivity for two biomass-derived alcohols.

Hydrocarbon adsorption in an aqueous environment: A computational study of alkyls on Cu(111).

Hydrocarbon chains are important intermediates in various aqueous-phase surface processes, such as CO2 electroreduction, aqueous Fischer-Tropsch synthesis, and aqueous phase reforming of biomass-derived molecules. Further, the interaction between water and adsorbed hydrocarbons represents a difficult case for modern computational methods. Here, we explore various methods for calculating the energetics of this interaction within the framework of density functional theory and explore trade-offs between the use of low water coverages, molecular dynamics approaches, and minima hopping for identification of low energy structures.

A systematic review and meta-analysis of cutaneous manifestations in late- versus early-onset systemic lupus erythematosus.

Objectives: Although systemic lupus erythematosus (SLE) most commonly occurs in reproductive-age women, some are diagnosed after the age of 50. Recognizing that greater than one-third of SLE criteria are cutaneous, we undertook a systematic review and meta-analysis to evaluate differences in cutaneous manifestations in early- and late-onset SLE patients.

Methods: We searched the literature using PubMed, CINAHL, Web of Science, and Cochrane Library.

Synergistic Effects of Alloying and Thiolate Modification in Furfural Hydrogenation over Cu-Based Catalysts.

Control of bimetallic surface composition and surface modification with self-assembled monolayers (SAMs) represent two methods for modifying catalyst activity and selectivity. However, possible synergistic effects of employing these strategies in concert have not been previously explored. We investigated the effects of modifying Cu/Al2O3 catalysts by alloying with Ni and modifying with octadecanethiol (C18) SAMs, using furfural hydrogenation as a probe reaction.

Controlling Catalytic Selectivity via Adsorbate Orientation on the Surface: From Furfural Deoxygenation to Reactions of Epoxides.

Specificity to desired reaction products is the key challenge in designing solid catalysts for reactions involving addition or removal of oxygen to/from organic reactants. This challenge is especially acute for reactions involving multifunctional compounds such as biomass-derived aromatic molecules (e.g.