Operando Generated Ordered Heterogeneous Catalyst for the Selective Conversion of CO₂ to Methanol

Abstract

The discovery of new materials for efficient transformation of carbon dioxide (CO 2 ) into desired fuel can revolutionize large-scale renewable energy storage and mitigate environmental damage due to carbon emissions. In this work, we discovered an operando generated stable Ni−In kinetic phase that selectively converts CO 2 to methanol (CTM) at low pressure compared to the state-of-the-art materials. The catalytic nature of a well-known methanation catalyst, nickel, has been tuned with the introduction of inactive indium, which enhances the CTM process. The remarkable change in the mechanistic pathways toward methanol production has been mapped by operando diffuse reflectance infrared Fourier transform spectroscopy analysis, corroborated by first-principles calculations. The ordered arrangement and pronounced electronegativity difference between metals are attributed to the complete shift in mechanism. The approach and findings of this work provide a unique advance toward the next-generation catalyst discovery for going beyond the state-of-the-art in CO 2 reduction technologies.

Regeneration of Active Surface Alloys during Cyclic Oxidation and Reduction: Oxidation of H2 on Pd/Ag(111)

“…Specifically, metastable structures of alloys may be the catalytic phase, as illustrated for nanoporous AgAu, 68,69 Ni-doped nanoporous Cu, 70 core−shell nanoparticles, 58 dilute Pd/Au nanoparticles, 71 and Ni−In intermetallic nanoparticles. 61 These catalytic studies further illustrate the principle that the active phase can be formed and regenerated under steady-state conditions; however, studies on single-crystal models that demonstrate cyclic generation of metastable active phases are lacking.…”

“…21,36,39,44,47,49−51,54−57,64−66 Hence, excursions between oxidizing and reducing conditions (cyclical redox conditions) can lead to substantial changes in catalyst morphology and composition and therefore catalyst performance. 17,58,60,61 Both thermodynamic and kinetic factors play a role in determining the structure and composition of alloy surfaces. Structures formed during deposition may not be the most thermodynamically stable; rather, they can be considered to be in quasi-equilibrium and are stable in certain temperature ranges.…”

“…64 Similar resegregation phenomena as a function of the adsorbate and temperature have been observed for CO 39,47,66,89 and acetylene 65 on Pd−Ag systems as well as other bimetallic systems that rearrange under oxidizing environments. 17,44,49,[54][55][56][57][58]60,61,64 By the third redox cycle, the intensities of the Pd and Pd x Ag 1−x alloy transitions remain constant, indicating that the near surface reaches a metastable surface phase and hence maintains Pd to within the top few surface layers.…”

“…Alloys have an added layer of complexity due to compositional changes that may occur due to changes in temperature and the presence of ambient gases. − ,− Temperature affects the mobility of metal atoms on the surface, which can lead to the formation of an alloy as demonstrated for Pt–Re catalysts − or the loss of the minority metal into the bulk. ,− Furthermore, both oxidizing and reducing gases induce dramatic changes in the surface composition of bimetallic systems, including single-crystal surfaces [Pd–Au(111), ,− PdAu/Mo(110), AuPd(100), ,, Pd/Ag(111), ,, Fe/Pt(111), Ni/Pt(111), and Pt 3 Ni­(111)], nanoparticles (Pd–Pt, Pd–Rh, Co–Pt, Pt–Cu, and Ni–Au), and supported catalysts (Pd–Au, Pt–Re, Pt–Ni, , Ni–In, and Pt–Cu). The specific pretreatment can influence the degree of alloying .…”

CO2 Utilization Through its Reduction to Methanol: Design of Catalysts Using Quantum Mechanics and Machine Learning

“…Often, more than one mechanism is proposed experimentally based on identification of some intermediates. In such a situation, theory is in a position to narrow down the most likely pathway or the mechanism by comparing intermediate energies and associated activation barriers (Cherevotan et al 2021 ). Structures of the catalyst-reacting species complex are useful to identify active sites on catalysts along with spectroscopic information.…”