A series of ZrO2-supported WOx catalysts were prepared using atomic layer deposition (ALD) with W(CO)6, and were then compared to a WOx/ZrO2 catalyst prepared via conventional impregnation. The types of sites present in these samples were characterized using temperature-programmed desorption/thermogravimetric analysis (TPD-TGA) measurements with 2-propanol and 2-propanamine. Weight changes showed that the WOx catalysts grew at a rate of 8.8 × 1017 W atoms/m2 per cycle. Scanning transmission electron microscopy/energy-dispersive spectroscopy (STEM-EDS) indicated that WOx was deposited uniformly, as did the 2-propanol TPD-TGA results, which showed that ZrO2 was completely covered after five ALD cycles. Furthermore, 2-propanamine TPD-TGA demonstrated the presence of three types of catalytic sites, the concentrations of which changed with the number of ALD cycles: dehydrogenation sites associated with ZrO2, Brønsted-acid sites associated with monolayer WOx clusters, and oxidation sites associated with higher WOx coverages. The Brønsted sites were not formed via ALD of WOx on SiO2. The reaction rates for 2-propanol dehydration were correlated with the concentration of Brønsted sites. While TPD-TGA of 2-propanamine did not differentiate the strength of Brønsted-acid sites, H–D exchange between D2O and either toluene or chlorobenzene indicated that the Brønsted sites in tungstated zirconia were much weaker than those in H-ZSM-5 zeolites.

We report the design and performance of a rapid pulse Joule heating (RPH) reactor with an in situ Raman spectrometer for highly endothermic, reversible reactions. We demonstrate it for methane dry reforming over a bimetallic PtNi/SiO2 catalyst that shows better performance than its monometallic counterparts. The catalyst temperature ramp rate can reach ∼14000 °C/s, mainly owing to the low thermal mass and resistivity of the heating element. Joule heating elements afford temperatures unachievable by conventional technology to enhance performance and more than double the energy efficiency. Dynamic electrification can increase syngas productivity and rate. Extensive characterizations suggest that pulse heating creates an in situ catalyst regeneration strategy that suppresses coke formation, sintering, and phase segregation, resulting in improved catalyst stability, under many conditions. Potentially driven by renewable electricity, the RPH can provide superb process advantages for high-temperature endothermic reactions and lead to negative carbon emissions.

We report the synthesis, optimization, and characterization of Co/SiO2 for ethane nonoxidative dehydrogenation. Co/SiO2 is synthesized via strong electrostatic adsorption using the widely available Co­(NO3)2 as the precursor. We demonstrate that high-temperature pretreatment (900 °C) in an inert atmosphere can significantly enhance the initial activity of the Co/SiO2 catalyst. X-ray absorption near-edge spectroscopy (XANES), temperature-programmed reduction (TPR), and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) suggest that highly dispersed Co­(II) clusters are more active than Co0 or CoO x nanoparticles. Fourier transform infrared (FTIR) and isopropanol (IPA) temperature-programmed desorption and density functional theory (DFT) calculations suggest that high-temperature treatment significantly increases the density of active Lewis acid sites, possibly via surface dehydroxylation of the catalyst.

Earth-abundant metals have recently been demonstrated as cheap catalyst alternatives to scarce noble metals for polyethylene hydrogenolysis. However, high methane selectivities hinder industrial feasibility. Herein, we demonstrate that low-temperature ex-situ reduction (350 °C) of coprecipitated nickel aluminate catalysts yields a methane selectivity of <5% at moderate polymer deconstruction (25–45%). A reduction temperature up to 550 °C increases the methane selectivity nearly sevenfold. Catalyst characterization (XRD, XAS, 27Al MAS NMR, H2 TPR, XPS, and CO-IR) elucidates the complex process of Ni nanoparticle formation, and air-free XPS directly after reaction reveals tetrahedrally coordinated Ni2+ cations promote methane production. Metallic and the specific cationic Ni appear responsible for hydrogenolysis of internal and terminal C–C scissions, respectively. A structure-methane selectivity relationship is discovered to guide the design of Ni-based catalysts with low methane generation. It paves the way for discovering other structure–property relations in plastics hydrogenolysis. These catalysts are also effective for polypropylene hydrogenolysis.

Valuable knowledge of catalysis is often hidden in a large amount of scientific literature. There is an urgent need to extract useful knowledge to facilitate scientific discovery. This work takes the first step toward the goal in the field of catalysis. Specifically, we construct the first information extraction benchmark data set that covers the field of catalysis and also develop a general extraction framework that can accurately extract catalysis-related entities from scientific literature with 90% extraction accuracy. We further demonstrate the feasibility of leveraging the extracted knowledge to help users better access relevant information in catalysis through an entity-aware search engine and a correlation analysis system.

The upgrading of heterocyclic biomass-derived oxygenates such as tetrahydrofurfuryl alcohol (THFA) via ringopening is a promising pathway to produce value-added diol molecules using renewable carbon sources. This study combines model surface experiments, first-principles calculations, and powder catalyst characterization and activity evaluation to unravel the nature of the Pt and WO x active sites and the reaction mechanism of the THFA ring-opening reaction on a WO x /Pt inverse oxide catalyst. Temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) measurements on model surfaces demonstrated that THFA ring opened on Pt(111) but underwent further decomposition due to its strong bonding with the surface. However, WO x deposited on Pt(111) altered the interaction strength between the ring-opened intermediate and the surface to a proper extent to facilitate the facile desorption of the desired 1,5-pentanediol (1,5-PeD) product. Density functional theory (DFT) calculations showed that WO x /Pt(111) could promote ring opening of THFA via an oxocarbenium ion-like transition state, which was stabilized by hydrogen bonding with the hydroxyl groups of WO x . The hydrogenation of the ring-opened 5-hydroxyvaleraldehyde intermediate to 1,5-PeD was then feasible via Brønsted acid sites present on WO x . Steady-state activity studies on the corresponding powder catalysts showed that the 1,5-PeD selectivity increased from 20% on Pt/SiO 2 to 65% on WO x /Pt/SiO 2 with 1 wt % WO x loading, consistent with model surface experiments and DFT calculations. This study demonstrates the feasibility of using model surface experiments and first-principles calculations to guide practical catalyst design, and provides a design strategy that can be applied to the selective ring-opening of relevant heterocyclic biomass-derived oxygenates.

There are few reports of microbial deconstruction or functionalization of the recalcitrant backbone of polyolefins. However, microbes can utilize polyolefin deconstruction products, including n-alkanes. Here, we combined chemical catalysis with bioconversion to valorize polyethylene (PE) deconstruction products. High-density PE (HDPE) was deconstructed via hydrogenolysis over a ruthenium on carbon catalyst. The resulting n-alkane mixture (C4–C35) was utilized as a feedstock for microbial consortia derived from soil from local recycling plants. We found two consortia that utilized the PE-deconstruction product mix as a sole carbon source. We adapted the consortia on a commercially available n-alkane mix to reduce the number of species present and enrich for enhanced alkane utilization. Both resulting enriched consortia utilized the PE-deconstruction product mix more effectively than the original (parent) consortia. The predominant metabolite produced from a model alkane hexadecane by both enriched consortia was a C16–C16 wax ester. Wax esters have considerable industrial value, with longer chain lengths (C32–C36) having the highest value. We identified two Rhodococcus aetherivorans strains that grow well on C24, indicating that this species is important for the functionalization of long-chain alkanes. This work demonstrates that enriched consortia from plastic-enriched environments can be combined with chemical catalysis to valorize PE.