Toward Computational Design of Catalysts for CO₂ Selective Reduction via Reaction Phase Diagram Analysis

Abstract

Chemical conversion of carbon dioxide (CO2) into value‐added chemicals, for example, ethanol, has been recognized to be one of the most effective ways of carbon sources cycling. However, the selectivity controlling of CO2 reduction is still a challenging problem due to the formation of a variety of products, such as methanol, methane, formic acid, and carbon monoxide, associating with complicated reaction mechanisms. Herein, a simple and effective theoretical analysis of “reaction phases diagram” to understand the selectivity of CO2 reduction, based on the principle of reaction free energies with sequential priority is proposed. Using this principle, the fundamental understanding of the formation of different products in CO2 reduction is rationalized. On the basis of reaction free energies’ analysis, the selectivity trends of CO2 reduction to methane, methanol, and ethanol from a number of experiments are discussed. At the end, the selectivity trends with a computer algorithm of searching full reaction pathways, explaining well the effects from catalyst sizes, substrate observed in experiments, are confirmed.

Toward computational design of chemical reactions with reaction phase diagram

“…The applications of reaction phase diagram have shown a great success understanding experimental results, where the predicted activity variations have been verified by several experiments. 22,[49][50][51][53][54][55]63 The volcano plot at the thermodynamic level indicates it is usually a reasonable prediction for electrocatalysis. 26 However, some thermochemical processes do occur in electrocatalysis, for instance, C-N bond synthesis and C-C coupling.…”

“…In the previous researches, total 236 possible pathways were obtained from the complete pathway analysis on the basis of 27 elementary steps for CO 2 reduction to ethanol. 22 In case 22 elementary steps (Table 1) were considered to establish the reaction phase diagram, it resulted in 40 possible pathways. where the (quasi) activity map was produced with two independent descriptors (CO* and OH* adsorption energies).…”

“…It was found that there are scaling relations between adsorption energies (Figure 1(a)) for different adsorbates over a series of catalysts, [18][19][20] which in principle makes it feasible to establish various trends of reaction free energies by a descriptor. [21][22] In addition, it was well known that reaction barriers are highly correlated with reaction free energies, namely, Brønsted-Evans-Polanyi (BEP) relations [23][24][25] (Figure 1(b)). Therefore, both thermodynamic and kinetic energies can be correlated well with proper descriptors.…”

Unveiling hydrocerussite as an electrochemically stable active phase for efficient carbon dioxide electroreduction to formate

“…Therefore, the reaction free energy as a linear function of G ad (*HCOO) could be obtained (Fig. 4a), which was defined as the reaction phase diagram in our previous report 48 . Besides, a two-dimensional map of activity and selectivity (Fig.…”

Direct Conversion of Syngas to Ethanol within Zeolite Crystals

“…21,36,44 On the basis of this knowledge, we built a 2D reaction phase diagram to investigate the selectivity of methane, methanol, and ethanol on transition metal (211) surfaces and on RhMn catalysts based on the reported adsorption energies scaling relationship. 49 As shown in Figure S28, in the left and lower region, the main product is methane because of the extremely strong adsorption between CO and metal surfaces, leading to full CO dissociation. For the right area, the CO adsorption is weak, resulting in the production of methanol without C-O dissociation.…”