We present a systematic study to investigate the effects of nonframework cations and the role of phonon scattering mechanisms on the thermal transport properties of zeolite LTA, via experiment and semiempirical lattice dynamics calculations. Our study is motivated by the increasing interest in accurate measurements and mechanistic understanding of the thermal transport properties of zeolite mat...

The influence of the zeolite framework structure on formation N 2 O during ammonia-SCR NO x was studied for three different copper-functionalized samples, namely Cu-SSZ-13 (CHA), Cu-ZSM-5 (MFI), and Cu-BEA (BEA).

We compare the adsorption properties of intact supported silicalite membranes with those of silicalite powder and of alumina supports using nitrogen and argon as adsorbates at 77 K. We disentangle contributions from the membrane and support and find that the support contributes significantly to the total quantity adsorbed due to its relative thickness. The micropore-filling regions of the adsor...

The downscaling of feature sizes in integrated circuits (IC) requires on-chip interconnects with low dielectric constant layers (low-k) that mitigate the increase in propagation delay and power consumption. Several candidate low-k materials based on porous silicates have been proposed. Whereas porosity is beneficial for lowering the dielectric constant, it has detrimental effects on the mechani...

The gas-phase carbonylation of dimethoxymethane (DMM) to form methyl methoxyacetate (MMAc) can be catalyzed by acid zeolites. This reaction is a critical step in the synthesis of monoethylene glycol (MEG), a widely used chemical, from synthesis gas. The mechanism of DMM carbonylation occurring on H-MFI and H-FAU zeolites has been investigated using density functional theory. We find that the re...

Quantum mechanics/molecular mechanics (QM/MM) models are an appealing method for performing zeolite simulations. In QM/MM, a small cluster chosen to encompass the active center is described by QM, while the rest of the zeolite is described by MM. In the present study, we demonstrate that the charges and Lennard-Jones parameters on Si and O must be chosen properly for QM/MM calculations of adsor...

The reduction of Cu(II) oxide species in siliceous matrixes of different porosity (MFI, FAU, MCM-48) and in alumosilicate MFI was studied by temperature-programmed reduction in hydrogen (TPR), by X-ray absorption fine structure (after stationary hydrogen treatments), and by transmission electron microscopy. It was found that the reduction may proceed in one or in two reduction steps. The two-st...