Catalytic Properties of 3D Graphene-Like Microporous Carbons Synthesized in a Zeolite Template

Catalysis for Carbon-Circularity: Emerging Concepts and Role of Inorganic Chemistry

Carbon circularity is crucial for achieving a circular economy but has wider implications and impacts with respect to the circularity of materials. It has an in-depth transformative effect on the economy. CO2 recycling is a critical component for this objective, with catalysis and inorganic chemistry playing a determining role in achieving this challenge. This concept paper presents some examples, as food for thought, of unconventional aspects in developing thermal and electro/photocatalysts for recycling CO2. The aspects discussed regard designing novel materials for CO2 thermo- or electro-conversion and developing novel nanostructured electrodes.

Production of Aromatic Hydrocarbons from Co-Hydropyrolysis of Biomass Components and HDPE with Application of Modified HZSM-5 Catalyst

Experiments were conducted in this study on the co-hydropyrolysis of three components of biomass (cellulose, hemicellulose, and lignin) and HDPE by using SR-Pd/Trap-HZ-5 as catalyst. To control the variable, we use the same experiment conditions in co-hydropyrolysis: Si/Al ratio of 50, Pd load 1 %, catalyst to reactant ratio of 1 : 10, 1 MPa, 400 °C, reaction time 1 h. Use XRD, TEM, BET, and NH3-TPD to confirm catalyst successful synthesis; use pine sawdust (PW) co-hydropyrolysis with HDPE to analyse catalytic activity; and use GC/MS to characterize the chemical composition of the bio-oil from the co-hydropyrolysis of biomass components and HDPE. The results show that cellulose has a significant synergistic effect with aromatic hydrocarbon production, whose selectivity was 93.3 %; hemicellulose has a synergistic effect; aromatic selectivity can reach 75.1 %; and a negative synergistic effect between lignin and HDPE was shown as the selectivity of aromatic hydrocarbons decreased from 62.1 % to 15.6 %.

Acidity: A Key Parameter in Zeolite-Templated Carbon Formation

This work reveals the crucial role of zeolite acidity in the synthesis of zeolite-templated carbons (ZTCs). While textural and chemical properties appear to be independent from acidity at a given synthesis temperature, the spin concentration in hybrid materials appears to be strongly impacted by the zeolite acid site concentration. The electrical conductivity of the hybrids and resulting ZTCs are closely related to the spin concentration in the hybrid materials. The amount of zeolite acid sites hence fundamentally impacts the electrical conductivity of the samples that spans over a range of four magnitudes. Electrical conductivity reveals as key parameter to describe the quality of ZTCs.

Pt-C interactions in carbon-supported Pt-based electrocatalysts

Carbon-supported Pt-based materials are highly promising electrocatalysts. The carbon support plays an important role in the Pt-based catalysts by remarkably influencing the growth, particle size, morphology, dispersion, electronic structure, physiochemical property and function of Pt. This review summarizes recent progress made in the development of carbon-supported Pt-based catalysts, with special emphasis being given to how activity and stability enhancements are related to Pt-C interactions in various carbon supports, including porous carbon, heteroatom doped carbon, carbon-based binary support, and their corresponding electrocatalytic applications. Finally, the current challenges and future prospects in the development of carbon-supported Pt-based catalysts are discussed.

Critical assessment of the performance of next-generation carbon-based adsorbents for CO2 capture focused on their structural properties

Carbon dioxide emissions and their sharply rising effect on global warming have encouraged research efforts to develop efficient technologies and materials for CO₂ capture. Post-combustion CO₂ capture by adsorption using solid materials is considered an attractive technology to achieve this goal. Templated materials, such as Zeolite Templated-Carbons and MOF-Derived Carbons, are considered as the next-generation carbon adsorbent materials, owing to their outstanding textural properties (high surface areas of ca. 4000 m² g^-1 and micropore volumes of ca. 1.7 cm³ g^-1) and their versatility for surface functionalization. These materials have demonstrated remarkable CO₂ adsorption capacities and CO₂/N₂ selectivities up to ca. 5 mmol g^-1 and 100, respectively, at 298 K and 1 bar, and low isosteric heat of adsorption at zero coverage of ca. 12 kJ mol^-1. Herein, a review of the advances in preparation of ZTCs and MDCs for CO₂ capture is presented, followed by a critical analysis of the effects of textural properties and surface functionality on CO₂ adsorption, including CO₂ uptake, CO₂/N₂ selectivity, and isosteric heat of adsorption. This analysis led to the introduction of a V_microx N-content factor to evaluate the interplay between N-content and textural properties to maximize the CO₂ uptake. Despite their promising performance in CO₂ uptake, further testing using mixtures and impurities, and studies on adsorbent regeneration, and cyclic operation are desirable to demonstrate the stability of the MDCs and ZTCs for large scale processes. In addition, advances in scale-up syntheses and their economics are needed.