Long-term stability of a 0.45% Au/TiO2 catalyst in the selective oxidation of glucose at optimised reaction conditions

Mirescu, Agnes; Berndt, H.; Martin, Andreas; Prüße, Ulf

doi:10.1016/j.apcata.2006.10.016

Cited by 89 publications

(68 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An effect of the support for the reaction was found by Ishida et al [20] comparing catalysts supported on metal oxides (TiO 2 , CeO 2 , ZrO 2 and Al 2 O 3 ) and one supported on C. The stability of the catalyst was proven by Baatz et al [21] who recycled 20 times at 40˝C an Au/Al 2 O 3 catalyst and from Mirescu et al [22] who recycled 17 times at 40˝C an Au/TiO 2 catalyst. In the present paper it was investigated the oxidation of glucose.…”

Section: Introductionmentioning

confidence: 76%

Effects of Support and Synthetic Procedure for Sol-Immobilized Au Nanoparticles

et al. 2016

View full text Add to dashboard Cite

Abstract:New gold catalysts supported on CeO 2 , ZrO 2 and TiO 2 were synthesized by two different techniques: deposition-precipitation and colloidal method. The role of the surfactant (PVA, PVP, THPC) was also investigated. The catalysts were tested in the oxidation of glucose to gluconic acid, in aqueous environment and under mild conditions (60˝C and atmospheric pressure). TEM and SEM analyses have shown that the small size of gold nanoparticles is a necessary condition, but not sufficient for a good conversion. In fact, for an active sample, we have verified that the excess of surfactant must be removed because it would coat the surface of the catalyst. The surfactant, however, should not be completely eliminated, since it has the fundamental role of stabilizing the sample preventing nanoparticles from aggregation. It was evidenced that both the synthetic approach and the kind of support affect the catalysts' activity. In fact, by focusing on the three different supports, with all the preparation methods, the ceria has proved to be the best support. This is due to its ability to obtain small gold nanoparticles and to its ability to accumulate oxygen. The most appropriate synthesis methodology proved to be the colloidal method with PVA. Recyclability issue was investigated too.

show abstract

Section: Introductionmentioning

confidence: 76%

Effects of Support and Synthetic Procedure for Sol-Immobilized Au Nanoparticles

et al. 2016

View full text Add to dashboard Cite

show abstract

“…[8][9][10] , other aldoses, [11] alcohols [12][13][14][15] or glyoxal. [16] Numerous reports deal with the preparation methods and characterisation of supported gold catalysts, [12,17,18] however, the syntheses are not easy to reproduce sometimes.…”

Section: Introductionmentioning

confidence: 99%

Oxidation of Citronellal to Citronellic Acid by Molecular Oxygen Using Supported Gold Catalysts

Martin¹,

Armbruster²,

Decker³

et al. 2008

ChemSusChem

View full text Add to dashboard Cite

The oxidation of citronellal to citronellic acid was studied using molecular oxygen as oxidant and gold-containing supported catalysts under aqueous conditions. The reactions were carried out at 60-90 degrees C, with 200 Nml min(-1) O2 and at pH values from 9 to 12. The alumina- or titania-supported catalysts were synthesized according to the deposition-precipitation procedure using urea or NaOH. Mechanistic studies have revealed that radical-initiated reactions lead to undesired by-products especially at pH <9, that is, the C=C bond is attacked and a diol is primarily formed probably via an epoxide intermediate. This side reaction can be suppressed to a large extent by increasing the pH to 12 and by raising the catalyst/oxygen ratio. Furthermore, detailed studies on the influence of reaction time, pH value, reactant concentration and amount of catalyst show that citronellic acid can be obtained in over 90% yield with total conversion of citronellal at pH 12 and a temperature of 80 degrees C.

show abstract

“…Dentre os ácidos orgânicos que podem ser produzidos, destaca-se o ácido glucônico, obtido através da oxidação da glicose (Carvalho et al, 2005;Mirescu et al, 2007). O ácido glucônico apresenta pequenas toxicidade e ação cáustica, além de fácil biodegradabilidade, podendo formar complexos solúveis com íons metálicos divalentes e trivalentes em soluções aquosas.…”

Section: Introductionunclassified

“…Entretanto, outra possibilidade de produção deste composto baseia-se na oxidação de soluções de glicose com oxigênio ou ar via catálise heterogênea, utilizando catalisadores de paládio, platina e ouro (Mirescu et al, 2007). Vários pesquisadores reportaram rendimentos em ácido glucônico acima de 95%, utilizando tais catalisadores em testes com soluções puras de glicose (Mirescu et al, 2007;Hermans e Devillers, 2002). A reação de oxidação ocorre a um pH levemente alcalino, próximo a 9, que deve ser mantido constante com uso de uma base (por exemplo NaOH) e a baixas temperaturas (50 ºC na maioria dos casos) (Hermans e Devillers, 2002;Abbadi e Bekkum, 1995).…”

Section: Introductionunclassified

Oxidação Catalítica De Hidrolisados Enzimáticos De Bagaço De Cana-De-Açúcar Pré-Tratado, Visando a Obtenção De Ácido Glicônico

Soares¹,

Mendes²,

Benachour

et al. 2015

Anais Do XX Congresso Brasileiro De Engenharia Química

View full text Add to dashboard Cite

dos resíduos mais abundantes das indústrias sucroalcooleiras, possui grande potencial como matéria-prima para a produção de energia (uso comum nessas indústrias) e produtos químicos de alto valor agregado, dos quais se destaca o bioetanol, cuja obtenção é ainda objeto de pesquisas científicas. No entanto, outros produtos, tais como, ácidos orgânicos e aldeídos, podem ser obtidos a partir desse resíduo. Um desses ácidos orgânicos que podem ser potencialmente produzidos é o ácido glicônico, obtido a partir da oxidação da glicose e que é bastante utilizado em indústrias farmacêuticas e alimentícias. Nesse trabalho, hidrolisados enzimáticos de bagaço de cana-de-açúcar pré-tratado (ricos em glicose) foram purificados e submetidos à oxidação catalítica com ar, utilizando Pd/Al 2 O 3 em reator batelada para a produção desse ácido. Os resultados mostraram uma conversão de 70% da glicose e um rendimento próximo a 80% em ácido glicônico após 4 h de reação.

show abstract

Long-term stability of a 0.45% Au/TiO2 catalyst in the selective oxidation of glucose at optimised reaction conditions

Cited by 89 publications

References 19 publications

Effects of Support and Synthetic Procedure for Sol-Immobilized Au Nanoparticles

Effects of Support and Synthetic Procedure for Sol-Immobilized Au Nanoparticles

Oxidation of Citronellal to Citronellic Acid by Molecular Oxygen Using Supported Gold Catalysts

Oxidação Catalítica De Hidrolisados Enzimáticos De Bagaço De Cana-De-Açúcar Pré-Tratado, Visando a Obtenção De Ácido Glicônico

Contact Info

Product

Resources

About