Catalyst design for enhanced sustainability through fundamental surface chemistry

Abstract

Decreasing energy consumption in the production of platform chemicals is necessary to improve the sustainability of the chemical industry, which is the largest consumer of delivered energy. The majority of industrial chemical transformations rely on catalysts, and therefore designing new materials that catalyse the production of important chemicals via more selective and energy-efficient processes is a promising pathway to reducing energy use by the chemical industry. Efficiently designing new catalysts benefits from an integrated approach involving fundamental experimental studies and theoretical modelling in addition to evaluation of materials under working catalytic conditions. In this review, we outline this approach in the context of a particular catalyst-nanoporous gold (npAu)-which is an unsupported, dilute AgAu alloy catalyst that is highly active for the selective oxidative transformation of alcohols. Fundamental surface science studies on Au single crystals and AgAu thin-film alloys in combination with theoretical modelling were used to identify the principles which define the reactivity of npAu and subsequently enabled prediction of new reactive pathways on this material. Specifically, weak van der Waals interactions are key to the selectivity of Au materials, including npAu. We also briefly describe other systems in which this integrated approach was applied.

New Architectures for Designed Catalysts: Selective Oxidation using AgAu Nanoparticles on Colloid‐Templated Silica

“…Herein, we demonstrate a modular and versatile approach for the design of an efficient bimetallic catalyst system based on the synthesis of a porous framework of silica with embedded bimetallic AgAu nanoparticles of uniform size and composition. This specific system establishes that catalytic activity and selectivity observed in support‐free nanoporous Ag 3 Au 97 alloys translates to the embedded nanoparticles, thus demonstrating that the modular synthesis process can be used to more generally test design principles. Indeed, the AgAu nanoparticles embedded in a colloid‐templated porous (CTP) SiO 2 is an active, selective, and robust catalyst for oxidative coupling of alcohols, similar to nanoporous Ag 3 Au 97 .…”

“…First, bimetallic nanoparticles often have chemical properties that are distinct from either individual metal, thus presenting tremendous potential for creating new, efficient catalysts . Secondly, Au‐based bimetallic materials are known to provide a clear predictive relationship between their surface reactivity with that of single‐crystal Au surfaces, enabling the translation of design principles from controlled conditions to operating conditions …”

Evolution of Metastable Structures at Bimetallic Surfaces from Microscopy and Machine-Learning Molecular Dynamics

“…13 Therefore, fundamental understanding of surface restructuring is crucial to enabling accurate prediction and engineering of catalyst performance. 14 Mechanistic and kinetic studies of surface restructuring at the atomic level have remained scarce and challenging. [15][16][17][18][19][20][21] Experimentally, it is very difficult to probe fast atomic motions with sufficient temporal resolution, even with techniques that possess surface and chemical sensitivities.…”

“…Pressure and temperature are enforced on the system with a Nosé-Hoover barostat (1000 δt = 5 ps coupling) and thermostat (100 δt = 0.5 ps coupling), respectively. 10,11,14 Table S1 lists the final optimized hyperparameters of the GP model. For validation, we Fig .…”

Summarizing comments on the discussion and a prospectus for urgent future action

“…Edwards and co-workers [34] have considered in depth all the thermodynamic and possible practical (materials) options for turning CO 2 into fuel. They also outline novel dry-reforming processes of hydrocarbons in which CO 2 Upon esterification using CO 2 as an activator, the carboxylate is converted into methyl ester with complete recycling of CO 2− 3 . This reaction enables the synthesis of dimethylfurandicarboxylate (dm FDCH) from furfural, a cheap, biomass-derived feedstock.…”