A Proxy for Oxygen Storage Capacity from High-throughput Screening and Automated Data Analysis

Oxygen storage and release is a foundational part of many key pathways in heterogeneous catalysis, such as the Mars-van Krevelen mechanism. However, direct measurement of oxygen storage capacity (OSC) is...</jats:p

Conformational control of structure and guest uptake by a tripeptide-based porous material

Chemical processes often rely on the selective sorting and transformation of molecules according to their size, shape and chemical functionality. For example, porous materials such as zeolites achieve the required selectivity through the constrained pore dimensions of a single structure.1 In contrast, proteins function by navigating between multiple metastable structures using bond rotations of the polypeptide,2,3 where each structure lies in one of the minima of a conformational energy landscape and can be selected according to the chemistry of the molecules interacting with the protein.3 Here we show that rotation about covalent bonds in a peptide linker can change a flexible metal-organic framework (MOF) to afford nine distinct crystal structures, revealing a conformational energy landscape characterised by multiple structural minima. The uptake of small molecule guests by the MOF can be chemically triggered by inducing peptide conformational change. This change transforms the material from a minimum on the landscape that is inactive for guest sorption to an active one. Chemical control of the conformation of a flexible organic linker offers a route to modify the pore geometry and internal surface chemistry and thus the function of open-framework materials

High-Throughput Discovery of Hf Promotion on the Formation of Hcp Co and Fischer-Tropsch Activity

A proxy-based high-throughput experimental approach was used to explore the stability and activity of Co-based Fischer Tropsch Synthesis catalysts with different promoters on various supports. The protocol is based on the estimation by XRD of active phase, Co, particle size and relative amounts of crystalline phases, Co to support. Sequential libraries samples enabled exploration of four Co loadings with five different promoters on six support materials. Catalysts stable to aging in syngas, displaying minimal change of particle size or relative area, were evaluated for their activity under industrial conditions. This procedure identified SiC as support for stable catalysts and a combination of Ru and Hf to promote the formation hcp Co. Unsupported bulk samples of Co with appropriate amounts of Ru and Hf revealed that the formation of hcp Co is independent of the support. The hcp Co containing catalyst presented the highest catalytic activity and C5+ selectivity amongst the samples tested in this study confirming the effectiveness of the proxy-based high-throughput method.</jats:p

Enhanced production and control of liquid alkanes in the hydrogenolysis of polypropylene over shaped Ru/CeO2 catalysts

The hydrogenolysis of polypropylene waste to liquid hydrocarbons offers a promising pathway for the chemical recycling of waste polymers. This work describes the importance of reaction conditions and support morphology to produce high liquid yields with enhanced control of chain length over highly active shaped and non-shaped Ru/CeO2 catalysts. The shaped 2 wt% Ru/CeO2 exhibit high liquid alkane yields (58–81%) when compared to the non-shaped 2 wt% Ru/CeO2 (liquid yield: 34–58%) under optimized reaction conditions (220 °C, 16 h, 30 bar H2). In particular, the 2 wt% Ru/CeO2 nanocube catalyst exhibits the highest activity yielding lighter hydrocarbons. This was rationalized to be a combination of small Ru cluster formation and enhanced metal-support interactions. The influence of larger Ru particles (≥1.5 nm) was confirmed mechanistically using a computational density functional theory study on the hydrogenolysis of pentane (C5) to determine the favorable formation of methane in the non-shaped Ru/CeO2 catalyst

Mesoporous Hydrophobic Polymeric Organic Frameworks with Bound Surfactants. Selective Adsorption of C₂H₆ versus CH₄

Mesoporous polymeric organic frameworks (mesoPOF)­s have been synthesized through surfactant mediated polymerization of phlorglucinol (1,3,5-trihydroxybenzene) and terephthalaldehyde under solvothermal conditions. The materials contain bound surfactant and exhibit hydrophobic properties. The mesoPOFs present high surface areas up to 1000 m² g^–1 and have pores of several size ranges from micropores to large mesopores depending on the amount of surfactant used. The adsorption uptakes of CO₂, C₂H₆, and CH₄ measured at 273 K at 1 bar are linearly correlated to the micropore volume. The mesoPOFs display high adsorption selectivity of C₂H₆ over CH₄ by a factor of 40, and this property is dictated by their pore diameter

Mesoporous Hydrophobic Polymeric Organic Frameworks with Bound Surfactants. Selective Adsorption of C₂H₆ versus CH₄

Mesoporous polymeric organic frameworks (mesoPOF)­s have been synthesized through surfactant mediated polymerization of phlorglucinol (1,3,5-trihydroxybenzene) and terephthalaldehyde under solvothermal conditions. The materials contain bound surfactant and exhibit hydrophobic properties. The mesoPOFs present high surface areas up to 1000 m² g^–1 and have pores of several size ranges from micropores to large mesopores depending on the amount of surfactant used. The adsorption uptakes of CO₂, C₂H₆, and CH₄ measured at 273 K at 1 bar are linearly correlated to the micropore volume. The mesoPOFs display high adsorption selectivity of C₂H₆ over CH₄ by a factor of 40, and this property is dictated by their pore diameter

Functional Monolithic Polymeric Organic Framework Aerogel as Reducing and Hosting Media for Ag nanoparticles and Application in Capturing of Iodine Vapors

Monolithic aerogels of polymeric organic framework (Mon-POF) with a high density of OH functional groups were synthesized through solvothermal polymerization of terephthalaldehyde and 1,5-dihydroxynaphthalene. This POF material presents high surface area of 1230 m² g^–1 having micro-, meso-, macropores, and low bulk density of 0.15 g cm^–3. The evolution of the porous properties is controlled with the polymerization rate. Mon-POF is stable under acidic and basic conditions. The presence of high number of OH functional groups provides the monolith with ion-exchange properties as well as reducing properties. The Mon-POF adsorbs Ag⁺ from aqueous solution to deposit Ag nanoparticles into the pores at a high loading content ∼25 wt % of the composite material. The Ag loaded monolith captures significant amount of I₂ vapor and fixes it effectively in the form of β-AgI

High‐Throughput Discovery of a Rhombohedral Twelve‐Connected Zirconium‐Based Metal‐Organic Framework with Ordered Terephthalate and Fumarate Linkers

We report a metal‐organic framework where an ordered array of two linkers with differing length and geometry connect [Zr(6)(OH)(4)O(4)](12+) clusters into a twelve‐connected fcu net that is rhombohedrally distorted from cubic symmetry. The ordered binding of equal numbers of terephthalate and fumarate ditopic carboxylate linkers at the trigonal antiprismatic Zr(6) core creates close‐packed layers of fumarate‐connected clusters that are connected along the single remaining threefold axis by terephthalates. This well‐defined linker arrangement retains the three‐dimensional porosity of the Zr cluster‐based UiO family while creating two distinct windows within the channels that define two distinct guest diffusion paths. The ordered material is accessed by a restricted combination of composition and process parameters that were identified by high‐throughput synthesis