Selective CO-to-acetate electroreduction via intermediate adsorption tuning on ordered Cu–Pd sites

Abstract

Electrochemical reduction of carbon monoxide (CO) has recently been emerging as a potential alternative for converting carbon emission into high-value multi-carbon products such as acetate. Nonetheless, the activity and selectivity for producing acetate have remained low. Herein, we developed an atomically ordered copper-palladium intermetallic compound (CuPd-IC) structure that achieved a high Faradaic e ciency of 70 ± 5% for CO-to-acetate production with a partial current density of 425 mA•cm − 2 . This corresponded to an acetate production rate of 4.0 mmol•h − 1 •cm − 2 , and 5.3 times of enhancement in acetate production compared to pure Cu. Structural characterizations and density functional theory calculations suggested that CuPd-IC presents a high density of Cu-Pd pairs that act as the active sites to enrich the surface CO coverage, stabilize the surface ethenone as a key acetate-path intermediate, and inhibit hydrogen evolution reaction, thus promoting acetate formation. Using a membrane electrode assembly device, the CuPd-IC catalyst enabled 100 hours of CO-to-acetate operation at 500 mA•cm − 2 and an average acetate Faradaic e ciency of 43%, producing ~ 2 mol acetate.

Tuning crystal-phase of bimetallic single-nanoparticle for catalytic hydrogenation

“…Bimetallic catalysts, consisting of a platinum-group metal and a late-transition metal, featured geometrical variation and electronic redistribution via metal–metal interactions and enhanced the activity and/or selectivity, strongly depending on the crystal-phase and the particle size 1 – 9 . PdCu nanoparticles in the chemically ordered body-centered cubic (B2) phase, for instance, showed pronouncedly increased activity (2–20 times) for the electro-conversion of energy-related molecules 10 – 15 and substantially promoted selectivity for the hydrogenation of multiple carbon–carbon bonds 16 , relative to the disordered face-centered cubic (fcc) ones. Experimental studies and theoretical calculations on PdCu model systems, mostly large, single-crystals or extended surfaces, have presumably proposed that Cu atom modulated the electron density and the geometric arrangement of Pd atom and thus altered the activation pathways of the reacting molecules 17 – 21 .…”

Shape-controllable and kinetically miscible Copper–Palladium bimetallic nanozymes with enhanced Fenton-like performance for biocatalysis

“…As shown in Fig. 3 e, both the centers of CuPd 3 nanozyme and Cu-foil are located at κ-space (about 7.95 ​Å −1 ) and R-space (about 2.25 ​Å), which are attributed by the Cu–Cu scattering signal [ 17 , 18 ]. The WT image of CuPc presents a center at κ-space (about 6.25 ​Å −1 ) and R-space (about 1.02 ​Å), revealing the typical signal of Cu–N coordinated center.…”

The Catalytic Reactivity of Alloys; Ethanol and Formic Acid Decomposition on Cu–Pd(110)

“…Alternatively well-ordered thin films can be produced, but most workers currently focus on single-site catalysts (e.g., dilute layers of Pd in Cu 32 ), and again, well-ordered mixed layers can be rather difficult to achieve in that way. Note that Ji et al 51 have also used aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) to atomically resolve the surface on large CuPd nanoparticles of the same body-centered cubic (bcc) bulk structure as used here.…”