The performance of supported metal catalysts can depend on many factors, including particle size and dispersion metal–support interactions, differentiation these effects is challenging because their interwoven relationship. Copper/ceria are well-known redox studied in the conversion CO CO2 via oxidation and/or reduction pathways. behaviors each species, Cu-CuO CeOx-CeO2, often suggested to be interlinked, allowing ceria-supported copper domains outperform species other, nonredox active...

Direct CO2 capture from atmospheric air is gaining increased attention as one of the most scalable negative carbon approaches available to tackle climate change if coupled with sequestration geologically. Furthermore, it can also provide for further utilization a globally uniform source, which especially advantageous economies without natural sources carbon-based feedstocks. Solid-supported amine-based materials are effective direct (DAC) due their high uptakes and acceptable sorption...

Surface chemical reactions of highly functional biomass derivatives such as furans with oxygenated ligands are often considered in terms the chemistry their individual groups, little focus on how multifunctionality affects surface chemistry. To probe these effects functionalized furans, temperature-programmed desorption (TPD) experiments and density theory (DFT) calculations were used to study thermal furfural, C4H3(CHO)O, furfuryl alcohol, C4H3(CH2OH)O Pd(111). The TPD results indicate that...

ZIF-8 is a crystalline microporous material that has been widely studied because of its thermal and chemical stability relative to other metal–organic frameworks (MOFs) potential for use in number gas adsorption, separation, catalysis applications. However, most studies focus on characterization the bulk structure ZIF-8, ignoring effect particle shape external surface these This report describes examined {110} {100} crystallographic facets under mildly acidic conditions. Though facet more...

Studies on aminopolymer/oxide composite materials for direct CO2 capture from air have often focused the prototypical poly(ethylenimine) (PEI) as aminopolymer. However, it is known that PEI will oxidatively degrade at elevated temperatures. This degradation has been ascribed to presence of secondary amines, which, when oxidized, lose their capacity. Here, we demonstrate use small molecule poly(propylenimine) (PPI) in linear and dendritic architectures supported silica adsorbent air....

Zeolitic imidazolate frameworks (ZIFs) are a set of nanoporous metal–organic (MOFs) with tunable porosity and functionality. Among MOFs, they also show relatively good stability respect to temperature humidity. These characteristics lead their possible applications in separation processes. In many practical processes, adsorbents exposed variety molecular species including acid gases. However, there is little knowledge the effects such gas exposure on adsorption properties ZIFs. Here, model...

Thiolate self-assembled monolayers (SAMs) were used to block specific active sites on Pd/Al2O3 during the hydrogenation of furfural elucidate site requirements for each process involved in this complex reaction network. Reactions performed uncoated, 1-octadecanethiol (C18) coated, and benzene-1,2-dithiol (BDT) coated catalysts. Selectivity among key pathways was sensitive SAM modifier, with increasing sulfur density strongly suppressing decarbonylation, less hydrogenation, minimally...

A series of alumina-supported Fe-based catalysts is prepared via a dry impregnation method in the presence phosphorus source (phosphate salt) and then used for catalytic dehydrogenation propane. Specifically, supported with Fe:P molar ratios 1:1, 2:1, 3:1 are their chemical composition, textural properties, redox properties characterized an array techniques. In nonoxidative (PDH) propane at 600 °C atmospheric pressure, most active catalyst (Fe:P ratio 3:1) exhibits 15% conversion >80% C3H6...

Poly(ethyleneimine)-impregnated sorbents are prepared using a hierarchical silica support with bimodal meso-/macroporosity. The behave unexpectedly during CO2 adsorption from simulated air and flue gases (400 ppm 10% CO2) at fixed temperature, as compared to systems built on commonly studied mesoporous materials. results demonstrate that (i) impregnation methods influence the efficacy of sorption performance (ii) show almost similar uptake capacities under 400 dry 30 °C, exhibiting step-like...

Aminopolymer-based solid sorbents have been widely investigated for the capture of CO2 from dilute streams such as flue gas or ambient air. However, oxidative stability studied aminopolymer, poly(ethylenimine) (PEI), is limited, causing it to lose its capacity after exposure oxygen at elevated temperatures. Here, we demonstrate use linear poly(propylenimine) (PPI), synthesized through a simple cationic ring-opening polymerization, more oxidatively stable alternative PEI with high and amine...

The behavior of metal–organic frameworks (MOFs) in the presence acid gases may be decisive their suitability for industrial applications. In this study, MIL-125 and MIL-125-NH2 were investigated with SO2 exposure dry, humid, aqueous environments. was found to unstable both humid acidic environments, while stable under these conditions, showing no change textural properties or visual degradation, as observed through SEM. Both materials water dry SO2, suggesting that reaction molecules form an...

Rising atmospheric CO2 levels have triggered recent research into the science of amine materials supported on hard, porous such as mesoporous silica or alumina. While can give high uptakes and good sorption kinetics, they are difficult to utilize in practical applications due difficulty contacting large volumes CO2-laden gases with powder without significant pressure drops sorbent attrition. Here, we describe a simple approach based impregnation permanently microporous polymer, PIM-1,...

Physical aging or degradation of amine-containing polymers and supported amine adsorbents is a critical issue that could limit the practical application such materials for CO2 capture. However, to date, there scarcity studies evaluate long-term stability amine-based sorbents without exclusive use accelerated tests. Here, we demonstrate extended (∼2 years) linear poly(propylenimine) (LPPI) confined in mesoporous silica (SBA-15) supports does not drastically impact adsorption performance under...

The efficient delivery of electrochemically in situ produced H2 can be a key advantage microbial electrosynthesis over traditional gas fermentation. However, the technical details on how to supply large amounts electric current per volume biocompatible manner remain unresolved. Here, we explored for first time flexibility complex 3D-printed custom electrodes fine-tune during electrosynthesis. Using model system H2-mediated electromethanogenesis comprised 3D fabricated carbon aerogel cathodes...

Aminopolymer-based sorbents are preferred materials for extraction of CO2 from ambient air [direct capture (DAC) CO2] owing to their high adsorption capacity and selectivity at ultra-dilute conditions. While those adsorptive properties important, the stability a sorbent is key element in developing high-performing, cost-effective, long-lasting that can be deployed scale. Along with process upsets, environmental components such as CO2, O2, H2O may contribute long-term instability. As such,...

Control of bimetallic surface composition and modification with self-assembled monolayers (SAMs) represent two methods for modifying catalyst activity selectivity. However, possible synergistic effects employing these strategies in concert have not been previously explored. We investigated the Cu/Al2O3 catalysts by alloying Ni octadecanethiol (C18) SAMs, using furfural hydrogenation as a probe reaction. Incorporation small amounts (Cu4Ni) improved catalytic while slightly reducing Further...

Direct air capture (DAC) technology is being explored as a pathway for reducing greenhouse gas emissions through the efficient removal of CO2 from atmosphere. However, there remains knowledge gap regarding structure–property–performance factors that impact behavior these systems in diverse, real-world environments. In aminopolymer-based DAC systems, diffusion tightly coupled with polymer mobility, which turn affected by large matrix variables, including interactions pore wall support,...

Temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) experiments were performed to determine the surface chemistry of benzyl alcohol on Pd(111) at varying initial coverage. At low coverage, adopts a flat lying structure where both phenyl ring are close surface. This decomposes through benzaldehyde intermediate undergoes decarbonylation produce benzene carbon monoxide. high an upright only function is bound extends into vacuum. The orientation...