Re-examination of the mechanism of HCOOH decomposition on Pt(111) in gas and solution phase

• 作 者: YuanyuanQi;HaoXu;DongjuZhang;ChengbuLiu;
• 机 构: Institute of Theoretical Chemistry,Shandong University,Jinan,250100
• 出 处: 第十二届全国量子化学会议
• 发表日期: 2014年期

　　Direct formic acid fuel cells(DFAFCs)have attracted substantial interest over the past decades due to their diverse advantages.Pt-based catalysts are known as the most excellent electrocatalysts for HCOOH oxidation.Nevertheless,they are easily poisoned by adsorbed CO-like species during HCOOH oxidation,where HCOOH at Pt electrode is oxidized to CO2 via a dual-pathway mechanism consisting of direct and indirect pathways.Most previous theoretical calculations give unexpected results that the indirect pathway(the dehydration of HCOOH to form CO intermediate)involves much higher barriers than the direct pathway(the dehydrogenation of HCOOH),which is clearly inconsistent with the observed easy CO poisoning of Pt-based catalysts.We re-examined the decomposition of HCOOH on Pt(111)in gas and solution phase to better understand the experimental observation by carrying out DFT calculations.The newly proposed decomposition pathways of HCOOH on Pt(111)show that the formation of CO involves comparable barriers with that of CO2,rationalizing the easy CO poisoning of Pt-based catalysts and improving our understanding for the mechanism of catalytic HCOOH oxidation on Pt(111).