Effect of electron density of Pt catalysts supported on alkali titanate nanotubes in cinnamaldehyde hydrogenation

Chin Yao Hsu, Tsai Chin Chiu, Meng Hung Shih, Wei Je Tsai, Wei Yi Chen, Chiu-Hsun Lin

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

Pt nanoparticles of diameter 0.5-1.5 nm were dispersed homogeneously on the inner and outer surfaces of alkali metal titanate nanotubes (M 2Ti3O7, M ) Li+, Na+, and K+) by ion exchange with Pt(NH3)2Cl 2 followed by calcination in ambient air at 673 K and reduction in H2 at 448 K. Both XPS and DRIFTS revealed that these titanate nanotubes donated their electrons to the Pt particles, yielding a negative Pt oxidation state, and that the degree of electron donation increased with the size of the alkali metal cation. The high electron density of the Pt particles promoted the activation of both CdC and CdO functional groups in cinnamaldehyde. Therefore, the order of the catalytic activity in the hydrogenation of cinnamaldehyde was Pt/KTNTs > Pt/ NaTNTs > Pt/LiTNTs. Since the Pt particles were very small, Pt/MTNTs selectively hydrogenated the CdC bond, yielding a hydrocinnamaldehyde with selectivities of 80-87% (at cinnamaldehyde conversions of 27-50%). The alkali metal ions of the titanate nanotubes were able to modify the mode of adsorption of cinnamaldehyde. Therefore, when a KOH promoter was added to the reaction mixture, cinnamyl alcohol became the main product and the cinnamyl alcohol selectivities were 77-83% (at cinnamaldehyde conversions of 49-74%).

Original languageEnglish
Pages (from-to)4502-4510
Number of pages9
JournalJournal of Physical Chemistry C
Volume114
Issue number10
DOIs
Publication statusPublished - 2010 Mar 18

Fingerprint

Alkalies
Alkali metals
Catalyst supports
alkali metals
Nanotubes
Hydrogenation
hydrogenation
Carrier concentration
alkalies
nanotubes
Alkali Metals
catalysts
alcohols
Alcohols
selectivity
Electrons
Calcination
roasting
Functional groups
Metal ions

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Cite this

Hsu, Chin Yao ; Chiu, Tsai Chin ; Shih, Meng Hung ; Tsai, Wei Je ; Chen, Wei Yi ; Lin, Chiu-Hsun. / Effect of electron density of Pt catalysts supported on alkali titanate nanotubes in cinnamaldehyde hydrogenation. In: Journal of Physical Chemistry C. 2010 ; Vol. 114, No. 10. pp. 4502-4510.
@article{a2921208259c4e8d8553b8a1ab82a429,
title = "Effect of electron density of Pt catalysts supported on alkali titanate nanotubes in cinnamaldehyde hydrogenation",
abstract = "Pt nanoparticles of diameter 0.5-1.5 nm were dispersed homogeneously on the inner and outer surfaces of alkali metal titanate nanotubes (M 2Ti3O7, M ) Li+, Na+, and K+) by ion exchange with Pt(NH3)2Cl 2 followed by calcination in ambient air at 673 K and reduction in H2 at 448 K. Both XPS and DRIFTS revealed that these titanate nanotubes donated their electrons to the Pt particles, yielding a negative Pt oxidation state, and that the degree of electron donation increased with the size of the alkali metal cation. The high electron density of the Pt particles promoted the activation of both CdC and CdO functional groups in cinnamaldehyde. Therefore, the order of the catalytic activity in the hydrogenation of cinnamaldehyde was Pt/KTNTs > Pt/ NaTNTs > Pt/LiTNTs. Since the Pt particles were very small, Pt/MTNTs selectively hydrogenated the CdC bond, yielding a hydrocinnamaldehyde with selectivities of 80-87{\%} (at cinnamaldehyde conversions of 27-50{\%}). The alkali metal ions of the titanate nanotubes were able to modify the mode of adsorption of cinnamaldehyde. Therefore, when a KOH promoter was added to the reaction mixture, cinnamyl alcohol became the main product and the cinnamyl alcohol selectivities were 77-83{\%} (at cinnamaldehyde conversions of 49-74{\%}).",
author = "Hsu, {Chin Yao} and Chiu, {Tsai Chin} and Shih, {Meng Hung} and Tsai, {Wei Je} and Chen, {Wei Yi} and Chiu-Hsun Lin",
year = "2010",
month = "3",
day = "18",
doi = "10.1021/jp9095198",
language = "English",
volume = "114",
pages = "4502--4510",
journal = "Journal of Physical Chemistry C",
issn = "1932-7447",
publisher = "American Chemical Society",
number = "10",

}

Effect of electron density of Pt catalysts supported on alkali titanate nanotubes in cinnamaldehyde hydrogenation. / Hsu, Chin Yao; Chiu, Tsai Chin; Shih, Meng Hung; Tsai, Wei Je; Chen, Wei Yi; Lin, Chiu-Hsun.

In: Journal of Physical Chemistry C, Vol. 114, No. 10, 18.03.2010, p. 4502-4510.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effect of electron density of Pt catalysts supported on alkali titanate nanotubes in cinnamaldehyde hydrogenation

AU - Hsu, Chin Yao

AU - Chiu, Tsai Chin

AU - Shih, Meng Hung

AU - Tsai, Wei Je

AU - Chen, Wei Yi

AU - Lin, Chiu-Hsun

PY - 2010/3/18

Y1 - 2010/3/18

N2 - Pt nanoparticles of diameter 0.5-1.5 nm were dispersed homogeneously on the inner and outer surfaces of alkali metal titanate nanotubes (M 2Ti3O7, M ) Li+, Na+, and K+) by ion exchange with Pt(NH3)2Cl 2 followed by calcination in ambient air at 673 K and reduction in H2 at 448 K. Both XPS and DRIFTS revealed that these titanate nanotubes donated their electrons to the Pt particles, yielding a negative Pt oxidation state, and that the degree of electron donation increased with the size of the alkali metal cation. The high electron density of the Pt particles promoted the activation of both CdC and CdO functional groups in cinnamaldehyde. Therefore, the order of the catalytic activity in the hydrogenation of cinnamaldehyde was Pt/KTNTs > Pt/ NaTNTs > Pt/LiTNTs. Since the Pt particles were very small, Pt/MTNTs selectively hydrogenated the CdC bond, yielding a hydrocinnamaldehyde with selectivities of 80-87% (at cinnamaldehyde conversions of 27-50%). The alkali metal ions of the titanate nanotubes were able to modify the mode of adsorption of cinnamaldehyde. Therefore, when a KOH promoter was added to the reaction mixture, cinnamyl alcohol became the main product and the cinnamyl alcohol selectivities were 77-83% (at cinnamaldehyde conversions of 49-74%).

AB - Pt nanoparticles of diameter 0.5-1.5 nm were dispersed homogeneously on the inner and outer surfaces of alkali metal titanate nanotubes (M 2Ti3O7, M ) Li+, Na+, and K+) by ion exchange with Pt(NH3)2Cl 2 followed by calcination in ambient air at 673 K and reduction in H2 at 448 K. Both XPS and DRIFTS revealed that these titanate nanotubes donated their electrons to the Pt particles, yielding a negative Pt oxidation state, and that the degree of electron donation increased with the size of the alkali metal cation. The high electron density of the Pt particles promoted the activation of both CdC and CdO functional groups in cinnamaldehyde. Therefore, the order of the catalytic activity in the hydrogenation of cinnamaldehyde was Pt/KTNTs > Pt/ NaTNTs > Pt/LiTNTs. Since the Pt particles were very small, Pt/MTNTs selectively hydrogenated the CdC bond, yielding a hydrocinnamaldehyde with selectivities of 80-87% (at cinnamaldehyde conversions of 27-50%). The alkali metal ions of the titanate nanotubes were able to modify the mode of adsorption of cinnamaldehyde. Therefore, when a KOH promoter was added to the reaction mixture, cinnamyl alcohol became the main product and the cinnamyl alcohol selectivities were 77-83% (at cinnamaldehyde conversions of 49-74%).

UR - http://www.scopus.com/inward/record.url?scp=77949463324&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77949463324&partnerID=8YFLogxK

U2 - 10.1021/jp9095198

DO - 10.1021/jp9095198

M3 - Article

AN - SCOPUS:77949463324

VL - 114

SP - 4502

EP - 4510

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

SN - 1932-7447

IS - 10

ER -