Immobilization of a heteropolyacid catalyst on the aminopropyl-functionalized mesostructured cellular foam (MCF) silica

Mesostructured cellular foam (MCF) silica with high surface area (>600 m²/g) and large pore volume (≈1.16 cm³/g) was synthesized via a surfactant templating method. The MCF silica was then modified by grafting 3-aminopropyl-triethoxysilane (APTES) to create a positive charge on the surface, and thus, to provide sites for the immobilization of H₃PMo₁₂O₄₀. By taking advantage of the overall negative charge of [PMo₁₂O₄₀]³⁻, the H₃PMo₁₂O₄₀ catalyst was chemically immobilized on the aminopropyl group of the surface modified MCF silica as a charge matching component. The mesopore structure of MCF silica was maintained even after the surface modification step and the subsequent immobilization step of H₃PMo₁₂O₄₀. The H₃PMo₁₂O₄₀ species were finely and molecularly dispersed on the surface modified MCF silica via chemical immobilization.     

Fabrication of double metal feram without degradation of remnant polarization by using Ir/IrOx capacitor contact barrier layer

Abstract

The capacitor contact barrier (CCB) structure was introduced to prevent both the Pt/Al reaction and the Ti effect to a SBT capacitor. TiN CCB layer could not perfectly block the Pt/Al reaction. And ferroelectric properties of SBT capacitor were degraded during back-end processes. So, we applied a new Ir/IrOx layer to the CCB layer. The SBT capacitor with the Ir/IrOx CCB layer exhibited higher delta polarization (dP～15 μC/cm²) after the metal-2 etching process, compared with the value in the case of the TiN CCB layer (dP～12μC/ cm²). Moreover, the dP uniformity was improved to 4% when we used the Ir/IrOx CCB layer, from the ～20% of the TiN CCB layer. And the defect formed by the Pt/Al reaction was not found in the Ir/IrOx CCB layer structure.     

Hydrogen and methane production from untreated rice straw and raw sewage sludge under thermophilic anaerobic conditions

Bioenergy produced from co-digestion of sewage sludge (SS) and rice straw (RS) as raw materials, without pretreatment and additional nutrients, was compared for the one-stage system for producing methane (CH₄) and the two-stage system for combined production of hydrogen (H₂) and CH₄ in batch experiments under thermophilic conditions. In the first stage H₂ fermentation process using untreated RS with raw SS, we obtained a high H₂ yield (21 ml/g-VS) and stable H₂ content (60.9%). Direct utilization of post-H₂ fermentation residues readily produced biogas, and significantly enhanced the CH₄ yield (266 ml/g-VS) with stable CH₄ content (75–80%) during the second stage CH₄ fermentation process. Overall, volatile solids removal (60.4%) and total bioenergy yield (8804 J/g-VS) for the two-stage system were 37.9% and 59.6% higher, respectively, than the one-stage system. The efficient production of bioenergy is believed to be due to a synergistically improved second stage process exploiting the well-digested post-H₂ generation residues over the one-stage system.