Combining Renewable Electricity and Renewable Carbon: Understanding Reaction Mechanisms of Biomass-Derived Furanic Compounds for Design of Catalytic Nanomaterials

Abstract

Conspectus Despite the growing deployment of renewable energy conversion technologies, a number of large industrial sectors remain challenging to decarbonize. Aviation, heavy transport, and the production of steel, cement, and chemicals are heavily dependent on carbon-containing fuels and feedstocks. A hopeful avenue toward carbon neutrality is the implementation of renewable carbon for the synthesis of critical fuels, chemicals, and materials. Biomass provides an opportune source of renewable carbon, naturally capturing atmospheric CO2 and forming multicarbon linkages and useful chemical functional groups. The constituent molecules nonetheless require various chemical transformations, often best facilitated by catalytic nanomaterials, in order to access usable final products. Catalyzed transformations of renewable biomass compounds may intersect with renewable energy production by offering a means to utilize excess intermittent electricity and store it within chemical bonds. Electrochemical catalytic processes can often offer advantages in energy efficiency, product selectivity, and modular scalability compared to thermal-driven reactions. Electrocatalytic reactions with renewable carbon feedstocks can further enable related processes such as water splitting, where value-adding organic oxidation reactions may replace the evolution of oxygen. Organic electroreduction reactions may also allow desirable hydrogenations of bonds without intermediate formation of H2 and need for additional reactors. This Account highlights recent work aimed at gaining a fundamental understanding of transformations involving biomass-derived molecules in electrocatalytic nanomaterials. Particular emphasis is placed on the oxidation of biomass derived furanic compounds such as furfural and 5-hydroxymethylfurfural (HMF), which can yield value-added chemicals, including furoic acid (FA), maleic acid (MA), and 2,5-furandicarboxylic acid (FDCA) for renewable materials and other commodities. We highlight advanced implementations of online electrochemical mass spectrometry (OLEMS) and vibrational spectroscopies such as attenuated total reflectance surface enhanced infrared reflection absorption spectroscopy (ATR-SEIRAS), combined with microkinetic models (MKMs) and quantum chemical calculations, to shed light on the elementary mechanistic pathways involved in electrochemical biomass conversion and how these paths are influenced by catalytic nanomaterials. Perspectives are given on the potential opportunities for materials development toward more efficient and selective carbon-mitigating reaction pathways.

Ampere-Level Electrolytic Coproduction of Formate with Coupled Carbon Dioxide Reduction and Selective Methanol Oxidation

“…Electrocatalytic reduction of carbon dioxide (CO 2 RR) to high-value chemicals is a key step toward the ever-challenging goal of global carbon neutralization. − At present, the development of practical electrolysis cells with CO 2 RR has been severely limited by the high overpotential of the anodic oxygen evolution reaction (OER), which also leads to high total power consumption and low value of byproduct oxygen, , substantially constraining their industrialization and commercialization. In the search for alternative anode reactions that can replace OER to better couple with the CO 2 RR, the oxidation of methanol, alcohol, urea, amines, biomass, and glucose has been considered suitable because of the relatively lower overpotentials and higher value-added products, yet the development of an ultrafast reaction kinetics that complements the state-of-the-art ampere-level cathodic CO 2 RR , is crucial for practical considerations. The selective oxidation of methanol to formic acid is a promising process as the product unit value is increased 3–5 times after conversion, , and formic acid is a valuable source of hydrogen-rich fuels, with a high hydrogen content of 53 g L –1 or 4.4 wt % .…”

Sensitivity Analysis of Electrochemical Double Layer Approximations on Electrokinetic Predictions: Case Study for CO Reduction on Copper

“…Density functional theory (DFT) modeling has been very useful in determining electrocatalytic reaction mechanisms and guiding the design of electrocatalytic materials. − However, major challenges exist in modeling the complex potential-dependent interplay between solvent, ions, and adsorbates at the electrode–electrolyte interface, which hinders progress in making accurate predictions of electrokinetics. − Changes in the composition and structure of the electrode–electrolyte interface, the electrochemical double layer (EDL), impact electrocatalytic activity and selectivity. − Despite advances in modeling the electrocatalytic interface, uncertainties in the solvent properties and ion distributions within the EDL pose challenges in modeling EDL effects. Representing the EDL within a DFT model inherently requires approximations because DFT cannot sample the dynamic ensemble of atomistic structures at the interface. , Thus, different mechanistic predictions can be reached depending on the DFT and EDL model approximations chosen.…”