Establishing a Link between Well-Ordered Pt(100) Surfaces and Real Systems: How Do Random Superficial Defects Influence the Electro-oxidation of Glycerol?

Autor(es)

Fernandez, Pablo S. ^[1] ; Gomes, Janaina Fernandes ^[1] ; Angelucci, Camilo A. ^[2] ; Tereshchuk, Polina ^[1] ; Martins, Caue A. ^[3] ; Camara, Giuseppe A. ^[4] ; Martins, Maria E. ^[5] ; Da Silva, Juarez L. F. ^[1] ; Tremiliosi-Filho, Germano ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos - Brazil

^[2] Fed Univ ABC UFABC, Ctr Nat & Human Sci CCNH, BR-5001 Santo Andre - Brazil

^[3] Fed Univ Grande Dourados, Fac Exact Sci & Technol, BR-79804970 Dourados, Mato Grosso Do - Brazil

^[4] Univ Fed Mato Grosso do Sul, Inst Chem, BR-79070900 Campo Grande, Mato Grosso Do - Brazil

^[5] CCT La Plata CONICET, Exact Sci Fac, Phys Chem Res Inst INIFTA, RA-1900 La Plata - Argentina

• Tipo de documento: Artigo Científico
• Fonte: ACS CATALYSIS; v. 5, n. 7, p. 4227-4236, JUL 2015.
• Citações Web of Science: 25

Resumo

Glycerol (GlOH) accumulation and its very low price constitute a real problem for the biodiesel industry. To overcome these problems, it is imperative to find new GlOH applications. In this context, electrochemistry arises as an important alternative to the production of energy or fine chemicals using GlOH as a reactant. To make these opportunities a reality, it is fundamentally necessary to understand how the glycerol electro-oxidation reaction (GEOR) occurs on catalysts used in real systems. Thus, research using model surfaces has generated the first insight into the electrochemistry of extremely complex real catalysts. Accordingly, in this work, we generate Pt(100) disturbed surfaces in a reproducible manner, carefully controlling the surface defect density. Then, GEOR is studied on well-ordered Pt(100) and on the disturbed Pt(100) surfaces in 0.5 M H2SO4 using cyclic voltammetry (CV) and in situ Fourier transform infrared spectroscopy (FTIR). The CV profile of GEOR consists of a single peak in the positive scan. The onset reaction displays the influence of defects present on the surface. On a surface with a high degree of disorder, the main GlOH oxidation process begins at 0.8 V vs RHE, whereas for well-ordered Pt(100), it starts 0.1 V earlier. FTIR experiments show the presence of carbon monoxide and carbonyl absorption bands. The electrochemical and spectroelectrochemical results are supported by density functional theory calculations showing that both CO and GlOH bind more strongly on disturbed than on well-ordered surfaces. Thus, our experiments show that Pt-CO (or other GlOH residue) bond breaking may be the GEOR rate-determining step. (AU)

• Processo FAPESP: 13/13749-0 - Conversão eletroquímica de glicerol em compostos de maior valor agregado: estudos do mecanismo e cinética reacional
• Beneficiário: Janaina de Souza Garcia
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/21045-2 - Predição teórica da estrutura, estabilidade termodinâmica, propriedades electronicas e reatividade de nanoclusters
• Beneficiário: Juarez Lopes Ferreira da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/16930-7 - Eletrocatálise V: processos eletrocatalíticos de interconversão entre as energias química e elétrica
• Beneficiário: Edson Antonio Ticianelli
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/01362-6 - Investigação do mecanismo de eletro-oxidação de combustíveis renováveis sobre monocristais e nanomateriais de Pt e Pd.
• Beneficiário: Pablo Sebastián Fernández
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado