Nanodiamonds @ N, P co-modified mesoporous carbon supported on macroscopic SiC foam for oxidative dehydrogenation of ethylbenzene

Folic Acid-Derived Low-dimensional carbons for efficient oxidative dehydrogenation of ethylbenzene

The oxidative dehydrogenation (ODH) of alkane is one of the most attractive routes in alkane production because of its favourable thermodynamic characteristic. Nitrogen-doped nanocarbons have demonstrated great potential in this reaction due to its cost-effective, high catalytic activity and stability. However, the influence of nitrogen on the catalytic properties of carbon materials is poorly understood due to the complexities of surface oxygen and nitrogen functional groups. Here we derive the performance descriptor that account for the nitrogen-dependent carbocatalysis in ODH reaction. To achieve this, we designed a set of nitrogen-doped nanocarbon materials with tunable nitrogen species by hydrothermal carbonization (HTC) treatment of the biomass folic acid (FA), which are applied in ODH of ethylbenzene. Among them, FA-180-1000 catalyst can achieve high ethylbenzene conversion (up to ∼62 %) and styrene selectivity (∼87 %), outperforming other HTC carbon-based catalysts. Structural characterizations and kinetic analyses revealed that nitrogen doping strongly interferes the charge polarization of CO site via electron transfer between CO, and nitrogen (mainly pyridine nitrogen and graphitic nitrogen) thus enhancing the reactivity of CO. Furthermore, the induction period during reaction process can be shortened by applying of sulfuric acid-assisted HTC method for constructing nitrogen-doped carbon catalyst with low crystallinity. The present work provides new insights into the contribution of nitrogen doping to the ODH reaction of carbon nanocatalysts, as well as guidance for the rational design of carbon catalysts for the conversion of hydrocarbons to high-value chemicals.

Polymers without Petrochemicals: Sustainable Routes to Conventional Monomers

Access to a wide range of plastic materials has been rationalized by the increased demand from growing populations and the development of high-throughput production systems. Plastic materials at low costs with reliable properties have been utilized in many everyday products. Multibillion-dollar companies are established around these plastic materials, and each polymer takes years to optimize, secure intellectual property, comply with the regulatory bodies such as the Registration, Evaluation, Authorisation and Restriction of Chemicals and the Environmental Protection Agency and develop consumer confidence. Therefore, developing a fully sustainable new plastic material with even a slightly different chemical structure is a costly and long process. Hence, the production of the common plastic materials with exactly the same chemical structures that does not require any new registration processes better reflects the reality of how to address the critical future of sustainable plastics. In this review, we have highlighted the very recent examples on the synthesis of common monomers using chemicals from sustainable feedstocks that can be used as a like-for-like substitute to prepare conventional petrochemical-free thermoplastics.

Porous Silicon Carbide (SiC): A Chance for Improving Catalysts or Just Another Active-Phase Carrier?

There is an obvious gap between efforts dedicated to the control of chemicophysical and morphological properties of catalyst active phases and the attention paid to the search of new materials to be employed as functional carriers in the upgrading of heterogeneous catalysts. Economic constraints and common habits in preparing heterogeneous catalysts have narrowed the selection of active-phase carriers to a handful of materials: oxide-based ceramics (e.g. Al₂O₃, SiO₂, TiO₂, and aluminosilicates-zeolites) and carbon. However, these carriers occasionally face chemicophysical constraints that limit their application in catalysis. For instance, oxides are easily corroded by acids or bases, and carbon is not resistant to oxidation. Therefore, these carriers cannot be recycled. Moreover, the poor thermal conductivity of metal oxide carriers often translates into permanent alterations of the catalyst active sites (i.e. metal active-phase sintering) that compromise the catalyst performance and its lifetime on run. Therefore, the development of new carriers for the design and synthesis of advanced functional catalytic materials and processes is an urgent priority for the heterogeneous catalysis of the future. Silicon carbide (SiC) is a non-oxide semiconductor with unique chemicophysical properties that make it highly attractive in several branches of catalysis. Accordingly, the past decade has witnessed a large increase of reports dedicated to the design of SiC-based catalysts, also in light of a steadily growing portfolio of porous SiC materials covering a wide range of well-controlled pore structure and surface properties. This review article provides a comprehensive overview on the synthesis and use of macro/mesoporous SiC materials in catalysis, stressing their unique features for the design of efficient, cost-effective, and easy to scale-up heterogeneous catalysts, outlining their success where other and more classical oxide-based supports failed. All applications of SiC in catalysis will be reviewed from the perspective of a given chemical reaction, highlighting all improvements rising from the use of SiC in terms of activity, selectivity, and process sustainability. We feel that the experienced viewpoint of SiC-based catalyst producers and end users (these authors) and their critical presentation of a comprehensive overview on the applications of SiC in catalysis will help the readership to create its own opinion on the central role of SiC for the future of heterogeneous catalysis.

A mutually isolated nanodiamond/porous carbon nitride nanosheet hybrid with enriched active sites for promoted catalysis in styrene production

A mutually isolated nanodiamond/porous carbon nitride nanosheet hybrid with enriched catalytic sites is fabricated by a facile two-step molten salt-oxidation strategy, generating an excellent catalyst for clean and energy-saving styrene production.

Advances in catalytic production processes of biomass-derived vinyl monomers

This review provides a summary and perspective for three bio-derived vinyl monomers – acrylic acid, methacrylic acid and styrene.

Coating of polydopamine on polyurethane open cell foams to design soft structured supports for molecular catalysts

Polydopamine-coated polyurethane open cell foams are used as structured supports for molecular catalysts through the covalent anchoring of alkoxysilyl arms by the catechol groups of the mussel-inspired layer. This strong bonding prevents their leaching. No alteration of the mechanical properties of the flexible support is observed after repeated uses of the catalytic materials.