Biography:

In the past Shawn D. Lin has collaborated on articles with Chia-Shiang Lin and Van-Huy Nguyen. One of their most recent publications is Noble metal catalysts for low-temperature naphthalene hydrogenation in the presence of benzothiophene. Which was published in journal Catalysis Today.

More information about Shawn D. Lin research including statistics on their citations can be found on their Copernicus Academic profile page.

Shawn D. Lin's Articles: (6)

Noble metal catalysts for low-temperature naphthalene hydrogenation in the presence of benzothiophene

AbstractPt/A12O3, Pd/A12O3, and Pd/TiO2 catalysts were compared to a commercial hydrotreating catalyst, NiMo/A12O3 for naphthalene hydrogenation inside tubing bombs at 553 K with a cold feed (at room temperature) of 6.99 MPa H2 and tridecane as the solvent. The noble metal catalysts were found to be significantly more active than NiMo/A12O3. A further study at a reaction temperature of 473 K showed that naphthalene hydrogenation over these noble metal catalysts can proceed even in the presence of benzothiophene at a concentration of 4200 ppm. Sulfur addition does decrease the activity of all the noble metal catalysts. However, Pd catalysts appear to have higher sulfur resistance than the Pt catalyst; Pd/TiO2 catalyst was found to be the most active and the least affected by benzothiophene among the three noble metal catalysts studied.

Influence of metal-support effects on acetophenone hydrogenation over platinum

AbstractThe vapor-phase acetophenone (AcPh) hydrognation reaction was studied over Pt/SiO2, Pt/η- Al2O3, Pt/SiO2 · Al2O3 and Pt/TiO2 catalysts to determine if the intramolecular selectivity to phenyl-ethanol (PhEt) could be enhanced by metal-support interactions (MSI). At low conversions ( < 10%), selectivities to PhEt above 95% were obtained over the Pt/TiO2 catalysts compared to 70–80% over Pt/SiO2 and Pt/η-Al2O3, and at high conversions ( > 70%) the selectivity remained above 80% over Pt/TiO2 after a HTR pretreatment. Very high yields of ethylbenzene (90–95%) were obtained with Pt/SiO2 · Al2O3 which are attributed to a bifunctional reaction involving PhEt dehydration to styrene on the acidic support followed by a hydrogenation step on the platinum. Activation energies for AcPh hydrogenation were typically between 5 and 10 kcal / mol, and turnover frequencies at 358 K did not vary markedly as they ranged from 0.028 to 0.058 s− at an AcPh pressure of 3 Torr. Significant deactivation was observed with platinum powder and Pt/SiO2, especially at a higher AcPh pressure of 10 Torr, but it was much less severe with the other catalysts. Turnover frequencies for the formation of phenylethanol, acetylcyclohexane, cyclohexylethanol, ethylbenzene, and ethylcyclohexane were also determined for these catalysts. This ability to increase intramolecular selectivity by favoring hydrogenation of a carbonyl bond is forwarded as additional evidence to support our MSI model invoking special sites at the metal-support interface which interact with the oxygen end of the carbonyl bond to activate it.

NotePlatinum states in citrate sols by EXAFS

AbstractPlatinum sols have been prepared by citrate reduction in the temperature range of 343–363 K. The Pt state in the solution was examined by EXAFS (extended X-ray absorption fine-structure spectroscopy). It did not show any PtPt bonding, a characteristic for reduced Pt sols. EXAFS model fitting further proved the presence of PtO with 4 oxygen neighbors, which suggests a tetraplanar coordination configuration. The possibility of neighboring Pt sharing oxygen ligand or the formation of PtOx is rejected by EXAFS model fitting. Citrate was found to be the most likely ligand to orient its oxygen end toward a charged Pt center. Thus we have revealed that the citrate treatment at this temperature range was clearly insufficient to reduce H2PtCl6(aq). Neither an extended period of reaction time nor an excess citrate reduced the Pt precursor. It is therefore highly recommended that the citrate sols should be carefully prepared and used.

Influence of co-feeds additive on the photo-epoxidation of propylene over V–Ti/MCM-41 photocatalyst

Highlights•The presence of H2O, or H2 co-feed changes the reaction activity and the catalyst stability during photo-epoxidation.•A small amount of H2O leads to enhanced activity and stability, but excess H2O will cause surface site blocking.•The catalyst stability increases when acetaldehyde (AA) is enhanced, suggesting that AA accumulation lead to deactivation.

Effects of the pretreatment of CuNi/SiO2 on ethanol steam reforming: Influence of bimetal morphology

Highlights•Calcination changed the alloy phase of the prepared CuNi/SiO2 catalysts into mixed phases of Cu-rich particles and NiO phase.•ESR performance improved after further reduction, especially in the acetaldehyde steam reforming selectivity.•The interface between NiO and Cu-rich nanoparticles may contribute to the enhanced acetaldehyde steam reforming selectivity.

In situ DRIFTS study on the methanol oxidation by lattice oxygen over Cu/ZnO catalyst

AbstractPrevious research shows that lattice oxygen of Cu catalyst participates in the methanol conversion. In this study, Cu/ZnO catalyst was pretreated to become fully oxidized, partially reduced, or completely reduced. In situ diffuse-reflectance infrared Fourier-transformed spectroscopy (DRIFTS) was used to analyze the methanol (MeOH) adsorption at 393 K and a following stepwise temperature-programmed desorption (sTPD). In addition to methoxy and formates appeared after MeOH adsorption, Cu/ZnO catalyst had formaldehyde but no CO2 while the Cu was completely reduced. When the Cu was in the oxidized or partially reduced states, CO2 formed and more formate appeared. Lattice oxygen participated in the MeOH conversion, and the reactivity was higher in the partially reduced Cu/ZnO than in the oxidized Cu/ZnO. This suggests that reduced Cu catalyzes the reaction between MeOH adspecies and lattice oxygen.

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