Open AccessSurface composition dominates the electrocatalytic reduction of CO 2 on ultrafine CuPd nanoalloys
Author(s) -
Chen Dong,
Wang Yanlei,
Liu Danye,
Liu Hui,
Qian Cheng,
He Hongyan,
Yang Jun
Publication year - 2020
Publication title -
carbon energy
Language(s) - English
Resource type - Journals
ISSN - 2637-9368
DOI - 10.1002/cey2.38
Subject(s) - selectivity , adsorption , catalysis , nanoparticle , galvanic cell , chemical engineering , desorption , composition (language) , chemistry , ethylene , materials science , particle size , inorganic chemistry , metallurgy , nanotechnology , organic chemistry , linguistics , philosophy , engineering
Preciously tuning the surface composition of noble metal nanoparticles with the particle size of only 2 nm or less by alloying with other metals represents a powerful strategy to boost their electrocatalytic selectivity. However, the synthesis of ultrafine nanoalloys and tuning their surface composition remain challenging. In this report, ultrafine CuPd nanoalloys with the particle size of ca. 2 nm are synthesized based on the galvanic replacement reaction between presynthesized Cu nanoparticles and Pd 2+ precursors, and the tuning of their surface compositions is also achieved by changing the atom ratios of Cu/Pd. For the electrocatalytic reduction of CO 2 , Cu 5 Pd 5 nanoalloys show the CO Faradaic efficiency (FE) of 88% at −0.87 V, and the corresponding mass activity reaches 56 A/g that is much higher than those of Cu 8 Pd 2 nanoalloys, Cu 3 Pd 7 nanoalloys and most of previously reported catalysts. Density functional theory uncovers that with the increase of Pd on the surface of the ultrafine CuPd nanoalloys, the adsorbed energy of both of intermediate COOH* and CO* to the Pd sites is strengthened. The Cu 5 Pd 5 nanoalloys with the optimal surface composition better balance the adsorption of COOH* and desorption of CO*, achieving the highest selectivity and activity. The difficult liberation of absorbed CO* on the surface of Cu 3 Pd 7 nanoalloys provides carbon source to favor the production of ethylene, endowing the Cu 3 Pd 7 nanoalloys with the highest selectivity for ethylene among these ultrafine CuPd nanoalloys.