Erdem Sasmaz

High-Throughput Investigation of Catalysts for JP-8 Fuel Cracking to Liquefied Petroleum Gas

Portable power technologies for military applications necessitate the production of fuels similar to LPG from existing feedstocks. Catalytic cracking of military jet fuel to form a mixture of C₂-C₄ hydrocarbons was investigated using high-throughput experimentation. Cracking experiments were performed in a gas-phase, 16-sample high-throughput reactor. Zeolite ZSM-5 catalysts with low Si/Al ratios (≤25) demonstrated the highest production of C₂-C₄ hydrocarbons at moderate reaction temperatures (623-823 K). ZSM-5 catalysts were optimized for JP-8 cracking activity to LPG through varying reaction temperature and framework Si/Al ratio. The reducing atmosphere required during catalytic cracking resulted in coking of the catalyst and a commensurate decrease in conversion rate. Rare earth metal promoters for ZSM-5 catalysts were screened to reduce coking deactivation rates, while noble metal promoters reduced onset temperatures for coke burnoff regeneration.

In situ spectroscopic investigation of a Pd local structure over Pd/CeO2 and Pd/MnOx–CeO2 during CO oxidation

The high activity observed on Pd impregnated MnOx–CeO2 solid solution catalysts for low temperature CO oxidation is investigated through in situ extended X-ray absorption fine structure (EXAFS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments. The change in the Pd local structure on CeO2 and MnOx–CeO2 is studied to identify the role of oxidized Pd nanoparticles during CO oxidation. EXAFS analysis of the calcined samples confirms the formation of PdO structures on CeO2 and MnOx–CeO2 supports. The structural model applied to the Ce1−xPdxO2−δ interaction phase could not predict the second and third near-neighbor coordination shells of Pd. Sintering and re-dispersion of Pd is observed on CeO2 during H2 reduction and subsequent oxidation with air. During CO oxidation, PdO species are reduced by CO on CeO2, forming a mixture of Pdn+/Pd0 species. These reduced Pd particles can be re-oxidized and re-dispersed on the CeO2 surface forming larger PdO crystallites. In the case of Pd/MnOx–CeO2, Pdn+ species can be stabilized during the reaction and no obvious Pd0 formation could be detected. Due to the formation of similar PdO species after CO oxidation on both CeO2 and MnOx–CeO2 supports, the different low temperature CO oxidation activities can be associated with the oxygen storage properties and oxygen mobility of the support.

High-Throughput Screening Using Fourier-Transform Infrared Imaging

ABSTRACT Efficient parallel screening of combinatorial libraries is one of the most challenging aspects of the high-throughput (HT) heterogeneous catalysis workflow. Today, a number of methods have been used in HT catalyst studies, including various optical, mass-spectrometry, and gas-chromatography techniques. Of these, rapid-scanning Fourier-transform infrared (FTIR) imaging is one of the fastest and most versatile screening techniques. Here, the new design of the 16-channel HT reactor is presented and test results for its accuracy and reproducibility are shown. The performance of the system was evaluated through the oxidation of CO over commercial Pd/Al 2 O 3 and cobalt oxide nanoparticles synthesized with different reducer-reductant molar ratios, surfactant types, metal and surfactant concentrations, synthesis temperatures, and ramp rates.