NO reduction and CO oxidation over Cu/Ce/Mg/Al mixed oxide catalyst in FCC operation

Simultaneous NO reduction and CO oxidation in the presence of O-2,H2O and SO2 over Cu/Mg/AUO (Cu-cat), Ce/Mg/Al/O (Ce-cat) and Cu/Ce/Mg/Al/O (CuCe-cat) were studied. At low temperatures (<340 degreesC), the presence of O-2 or H2O enhanced the activity of CuCe-cat for NO and CO conversions, but significantly suppressed the activity of Cu-cat and Ce-cat, At high temperature (720 degreesC), the presence of O-2 or H2O had no adverse effect on the NO and CO conversions over these catalysts. The addition of SO2 to NO + CO + O-2 + H2O system had no effect on the, reaction of CO + O-2 over Cu-cat, but deactivated this catalyst for NO + CO and CO + H2O reactions; over Ce-cat, all of these reactions of NO + CO, CO + O-2 and CO + H2O were suppressed significantly; over CuCe-cat, NO + CO and CO + O-2 reactions were not affected while the reaction of CO + H2O was slightly inhibited. (C) 2002 Elsevier Science B.V. All rights reserved.

Interface of chip-based capillary electrophoresis-inductively coupled plasma-atomic emission spectrometry (CE-ICP-AES)

An interface of chip-based capillary electrophoresis (CE)-inductively coupled plasma-atomic emission spectrometry (ICP-AES) that is based on cross-flow nebulization has been developed. A polydimethylsiloxane (PDMS) CE-chip with conventional cross channel layout was used. A stainless steel tube was placed orthogonal to the exit of the CE separation channel for cross flow nebulization. A supplementary flow of buffer solution at the channel exit was used to improve nebulization efficiency. Two capillaries were inserted into the CE chip near the inlet of the separation channel for sample and buffer solution injection. Syringe pumps were used to manipulate the flow rate and flow direction of the sample, buffer, and supplementary buffer solution. Peak broadening due to the shape (bulb and tube-shaped) and size of the spray chambers was studied. The smaller tube-shaped spray chamber was used because of smaller peak broadening effect due to aerosol transport. The nebulization and transport efficiency of the CE-ICP interface was approximately 10%. Ba2+ and Mg2+ ions were eluted from the CE-chip within 30 s. Resolution of the Ba2+ and Mg2+ peaks was 0.7 using the chip-based CE-ICP-AES system.