Transforming how plastics are made, unmade, and remade through innovative research and diverse partnerships that together foster environmental stewardship is critically important to a sustainable future. Designing, preparing, and implementing polymers derived from renewable resources for a wide range of advanced applications that promote future economic development, energy efficiency, and environmental sustainability are all central to these efforts. In this Chemical Reviews contribution, we take a comprehensive, integrated approach to summarize important and impactful contributions to this broad research arena. The Review highlights signature accomplishments across a broad research portfolio and is organized into four wide-ranging research themes that address the topic in a comprehensive manner: Feedstocks, Polymerization Processes and Techniques, Intended Use, and End of Use. We emphasize those successes that benefitted from collaborative engagements across disciplinary lines.

Conventional catalyst design has enhanced reactivity and product selectivity through control of surface thermochemistry by tunable surface composition and the surrounding environment (e.g., pore structure). In this work, the prospect for electric field towards controlling product selectivity and reaction networks on the Pt(111) surface was evaluated with periodic density functional theory (DFT) calculations in concert with machine learning (ML) algorithms. Linear scaling relationships (LSRs) for adsorption energies of surface species in electric field were shown to: (i) be distinct as compared to zero-field LSRs across metals, and (ii) linearly correlate with adsorption energies of H* rather than the binding element. The slope of LSRs linearly correlated with the zero-field dipole moment. A random forest ML regression algorithm predicted field-dependent adsorption energies with a mean absolute error (0.12 eV) comparable to DFT. Overall, this study identifies the path forward for electric field-assisted catalysis, specifically towards catalyst poisoning, product selectivity, and control of reaction pathways. File list (2) download file view on ChemRxiv Manuscript.pdf (1.45 MiB) download file view on ChemRxiv Supporting_Information.pdf (1.79 MiB)

This work describes the design and implementation of an automated device for catalytic materials testing by direct modifications to a gas chromatograph (GC). The setup can be operated as a plug-flow isothermal reactor and enables the control of relevant parameters such as reaction temperature and reactant partial pressures directly from the GC. High-quality kinetic data (including reaction rates, product distributions, and activation barriers) can be obtained at almost one-tenth of the fabrication cost of analogous commercial setups. With these key benefits including automation, low cost, and limited experimental equipment instrumentation, this implementation is intended as a high-throughput catalyst screening reactor that can be readily utilized by materials synthesis researchers to assess the catalytic properties of their synthesized structures in vapor-phase chemistries.

Co-feeding an inert and site-selective chemical titrant provides desirable selectivity tuning when titrant adsorption is favored over side reaction pathways on a solid acid catalyst. Here, a selectivity enhancement from 61 to 84 C % was demonstrated for methyl lactate dehydration to methyl acrylate and acrylic acid over a NaY zeolite catalyst using amines as the co-fed titrants to suppress side reactions on in situ-generated Brønsted acid sites (BASs). The effectiveness of BAS titration was evaluated by considering both the basicity and steric properties of the titrant molecule with the goal to maximize the selectivity enhancement. The presence of electron-donating alkyl functional groups not only enhances amine basicity but also introduces additional steric constraints to the molecule with respect to the pore dimensions of the NaY zeolite. While higher basicity of titrant amines favors stronger adsorption on BASs, steric limitations hinder site binding through contributions from internal diffusion limitations and local steric repulsion between the titrant and the zeolite wall around the BAS. Titrant bases with proton affinities above ∼1040 kJ/mol and sizes below 85% of the NaY supercage window or pore diameter are predicted to afford dehydration selectivities above 90 C % to acrylate products.

<p>Conventional catalyst design has enhanced reactivity and product selectivity through control of surface thermochemistry by tunable surface composition and the surrounding environment (e.g., pore structure). In this work, the prospect for electric field towards controlling product selectivity and reaction networks on the Pt(111) surface was evaluated with periodic density functional theory (DFT) calculations in concert with machine learning (ML) algorithms. Linear scaling relationships (LSRs) for adsorption energies of surface species in electric field were shown to: (i) be distinct as compared to zero-field LSRs across metals, and (ii) linearly correlate with adsorption energies of H* rather than the binding element. The slope of LSRs linearly correlated with the zero-field dipole moment. A random forest ML regression algorithm predicted field-dependent adsorption energies with a mean absolute error (0.12 eV) comparable to DFT. Overall, this study identifies the path forward for electric field-assisted catalysis, specifically towards catalyst poisoning, product selectivity, and control of reaction pathways.</p>