RETRACTED ARTICLE: Theory-guided Sn/Cu alloying for efficient CO2 electroreduction at low overpotentials
Authors: Yi Cui
Bofei Liu
Hans-Georg Steinrück
Karen Chan
Yuzhang Li
Michael F. Toney
Xueli Zheng
Jing Tang
Kipil Lim
Jiangyan Wang
Yongfei Ji
Journal: Nature Catalysis (2019)
Discipline: CHEMISTRY
Keywords: Electrochemical CO2 reduction; formate generation; CuSn3 catalysts; alloying; selectivity

Abstract: Electrochemical CO2 reduction to formate provides an avenue to reduce globally accelerating CO2 emissions and produce value-added products. Unfortunately, high selectivity in formate electrosynthesis has thus far only been achieved at highly cathodic potentials. Here we use density functional theory to investigate the effect of alloying Cu and Sn on the activity and selectivity towards formate. A theoretical thermodynamic analysis of the reaction energetics suggests that the incorporation of copper into tin could suppress hydrogen evolution and CO production, thus favouring formate generation. Consistent with theoretical trends, the designed CuSn3 catalysts by co-electrodeposition exhibit a Faradaic efficiency of 95% towards formate generation at \u22120.5\u2009V versus RHE. Furthermore, the catalysts show no degradation over 50\u2009h of operation. In situ Sn L3-edge and Cu K-edge X-ray absorption spectroscopy indicate electron donation from Sn to Cu, which indicates positive oxidation states of Sn in CuSn3 under operating conditions. The electroreduction of carbon dioxide to formate represents a desirable strategy for the production of fuels and commodity chemicals. Now, guided by density functional theory, Cui and colleagues report CuSn3 alloys that exhibit high activity and selectivity for formate production from CO2 electroreduction at potentials as low as \u22120.5\u2009V versus RHE.

Retracted: Yes

PubPeer comments:
 Figure 4f, Stability test of CuSn3 at u2212 0.5 V versus RHE (green symbols, Faradaic efficiency; black, current density), looks like duplicating some data. ![file] , 
 This is the graph, imported into Illustrator and where the line width is made smaller so all the details show better: ![file] , 
 Here is a plot where the data (blue curve) is superimposed and shifted by one  repeating unit , so the correlation in the noise is seen clearly: ![file] And zooming in: ![file] , 
 Another paper with exactly repeating noise: https: pubpeer.com publications A4ACA84631D57F762FF3A2E362492B , 
 #3 For the benefit of others, I have downloaded the pdf file and reduced the stroke of the line in Figure 4f from 1pt to 0.1 pt and highlighted the repeating parts. Now it is obvious that the data in this figure is copy pasted. ![file] , 
 25 June 2020: u201cNature Catalysis is publishing an editorial expression of concern on this article because of a repeating noise pattern in the chronoam- perometry plot of Fig. 4f. The authors have informed us that the raw data for this plot is unavailable. The authors have provided new experimental data to support the findings and we are currently investigating the issue further, in consultation with independent experts. We will provide an update once a conclusion is reached. All authors agree with the publication of this note.u201d , 
 5 May 2021: *u201cWe the authors are retracting this Article as we are unable to fully explain a pseudo-periodic noise pattern in the chronoamperometry plot of Fig. 4f. The raw data for this plot was lost and we are unable to reproduce the noise pattern under the same conditions originally reported. These issues reduce our full confidence in the performance of the catalyst reported in the study and we therefore wish to retract the Article.u201d* , 
 The retraction notice looks shockingly similar to the 1st retraction of Nature Chemistry by Chergui and coworkers, which is also covered here and and Retraction Watch: https: retractionwatch.com 2017 07 13 nature-chemistry-issues-first-retraction Back then, the authors were also citing data integrity issues, which becomes the most common form of scientific misconduct and also  could not provide the raw data to confirm their findings and could not reproduce the figures because the experimental set-up had been dismantled. The authors subsequently requested the paper be retracted because the issues undermined u201cour full confidence in the integrity of the study.u201d , 
 #7 The official retraction notice is available at: https: www.nature.com articles s41929-021-00619-9 , 
 High-profile retraction has been covered by the online news media:  Burst!Top materials scientist Cui Yi s research results have been retracted: the original data is no longer available https: inf.news en science 5f42748ca26245849e9fb34ca6fa0675.html , 
 As commented on the news article  Stanford Retraction , a very similar  pseudo-periodic noise pattern has been detected in yet another paper on pubpeer at https: pubpeer.com publications A4ACA84631D57F762FF3A2E362492B. ,