Redesign chemical processes to substitute the use of fossil fuels: A viewpoint of the implications on catalysis

Induction Heating for the Electrification of Catalytic Processes

The increasing availability of electrical energy generated from clean, low-carbon, renewable sources like solar and wind power is paving the way for a more sustainable future. This has resulted in a growing trend in the chemical industry to increase the share of electricity use in chemical processes, particularly catalytic ones. This shift towards electrifying catalytic processes offers significant environmental benefits. Current practices rely heavily on fossil fuel-based burners, primarily using natural gas, which contribute significantly to greenhouse gas emissions. Therefore, replacing fossil fuels with electricity can significantly reduce the carbon footprint associated with chemical production. Additionally, the energy-intensive production of metal catalysts used in these processes further exacerbates the environmental impact. This review focuses on the electrification of chemical processes, particularly using induction heating (IH), as a method to reduce the environmental impact of both catalyst production and operation. IH shows promise compared to conventional heating methods, since it offers a cleaner, more efficient, and precise way to heat catalysts in chemical processes by directly generating heat within the catalyst itself. It can potentially even enhance the reaction performance through its influence on the reaction mechanism. By exploring recent advancements in IH-driven catalytic processes, the review delves into how this method is revolutionizing catalysis by enhancing performance, selectivity, and sustainability. It highlights recent breakthroughs and discusses perspectives for further exploration in this rapidly developing field.

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.

Directing the Selectivity of Oxygen Reduction to Water by Confining a Cu Catalyst in a Metal Organic Framework

Electrocatalysis is to play a key role in the transition towards a sustainable chemical and energy industry and active, stable and selective redox catalysts are much needed. Porous structures such as metal organic frameworks (MOFs) are interesting materials as these may influence selectivity of chemical reactions through confinement effects. In this work, the oxygen reduction catalyst Cu-tmpa was incorporated into the NU1000 MOF. Confinement of the catalyst within NU1000 steers the selectivity of the oxygen reduction reaction (ORR) towards water rather than peroxide. This is attributed to retention of the obligatory H2 O2 intermediate in close proximity to the catalytic center. Moreover, the resulting NU1000|Cu-tmpa MOF shows an excellent activity and stability in prolonged electrochemical studies, illustrating the potential of this approach.

Advanced (photo)electrocatalytic approaches to substitute the use of fossil fuels in chemical production

Electrification of the chemical industry for carbon-neutral production requires innovative (photo)electrocatalysis. This study highlights the contribution and discusses recent research projects in this area, which are relevant case examples to explore new directions but characterised by a little background research effort. It is organised into two main sections, where selected examples of innovative directions for electrocatalysis and photoelectrocatalysis are presented. The areas discussed include (i) new approaches to green energy or H2 vectors, (ii) the production of fertilisers directly from the air, (iii) the decoupling of the anodic and cathodic reactions in electrocatalytic or photoelectrocatalytic devices, (iv) the possibilities given by tandem/paired reactions in electrocatalytic devices, including the possibility to form the same product on both cathodic and anodic sides to "double" the efficiency, and (v) exploiting electrocatalytic cells to produce green H2 from biomass. The examples offer hits to expand current areas in electrocatalysis to accelerate the transformation to fossil-free chemical production.

Catalysis for e-Chemistry: Need and Gaps for a Future De-Fossilized Chemical Production, with Focus on the Role of Complex (Direct) Syntheses by Electrocatalysis

The prospects, needs and limits in current approaches in catalysis to accelerate the transition to e-chemistry, where this term indicates a fossil fuel-free chemical production, are discussed. It is suggested that e-chemistry is a necessary element of the transformation to meet the targets of net zero emissions by year 2050 and that this conversion from the current petrochemistry is feasible. However, the acceleration of the development of catalytic technologies based on the use of renewable energy sources (indicated as reactive catalysis) is necessary, evidencing that these are part of a system of changes and thus should be assessed from this perspective. However, it is perceived that the current studies in the area are not properly addressing the needs to develop the catalytic technologies required for e-chemistry, presenting a series of relevant aspects and directions in which research should be focused to develop the framework system transformation necessary to implement e-chemistry.

Low-Temperature Atmospheric Pressure Plasma Processes for the Deposition of Nanocomposite Coatings

Low-temperature atmospheric pressure (AP) plasma technologies have recently proven to offer a range of interesting opportunities for the preparation of a variety of nanocomposite (NC) coatings with different chemical compositions, structures, and morphologies. Since the late 2000s, numerous strategies have been implemented for the deposition of this intriguing class of coatings by using both direct and remote AP plasma sources. Interestingly, considerable progress has been made in the development of aerosol-assisted deposition processes in which the use of either precursor solutions or nanoparticle dispersions in aerosol form allows greatly widening the range of constituents that can be combined in the plasma-deposited NC films. This review summarizes the research published on this topic so far and, specifically, aims to present a concise survey of the developed plasma processes, with particular focus on their optimization as well as on the structural and functional properties of the NC coatings to which they provide access. Current challenges and opportunities are also briefly discussed to give an outlook on possible future research directions.

A Numerical Investigation of Electrically-Heated Methane Steam Reforming Over Structured Catalysts

The use of electric energy as an alternative system to provide heat of reaction enables the cut-off of CO2 emissions of several chemical processes. Among these, electrification of steam methane reforming results in a cleaner production method of hydrogen. In this work, we perform for the first time a numerical investigation of a compact steam reforming unit that exploits the electrical heating of the catalyst support. First, for such unit we consider the optimal thermodynamic conditions to perform the power to hydrogen conversion; the process should be run at atmospheric pressure and in a close temperature range. Then, among possible materials currently used for manufacturing structured supports we identify silicon carbide as the best material to run electrified steam reforming at moderate voltages and currents. The temperature and concentration profiles in idealized units are studied to understand the impact of the catalyst geometry on the process performances and open-cell foams, despite lower surface to volume show the best potential. Finally, the impact of heat losses is analyzed by considering different operative conditions and reactor geometries, showing that it is possible to obtain relatively high thermal efficiencies with the proposed methodology.