BETA Zeolite Thin Films Supported on Honeycomb Monoliths with Tunable Properties as Hydrocarbon Traps under Cold-Start Conditions

A high percentage of hydrocarbon (HC) emissions from gasoline vehicles occur during the cold-start period. Among the alternatives proposed to reduce these HC emissions, the use of zeolites before the three-way catalyst (TWC) is thought to be very effective. Zeolites are the preferred adsorbents for this application; however, to avoid high pressure drops, supported zeolites are needed. In this work, two coating methods (dip-coating and in situ crystallization) are optimized to prepare BETA zeolite thin films supported on honeycomb monoliths with tunable properties. The important effect of the density of the thin film in the final performance as a HC trap is demonstrated. A highly effective HC trap is prepared showing 100 % toluene retention, accomplishing the desired performance as a HC trap, desorbing propene at temperatures close to 300 °C, and remaining stable after cycling. The use of this material before the TWC is very promising, and works towards achieving the sustainability and environmental protection goals.

La aplicación de las medidas correctivas de control de la estabilidad presupuestaria y sostenibilidad financiera a las subvenciones

A través del presente trabajo se pretende analizar algunas de las medidas correctivas que sobre la Administración pública impone la LOEPSF. En concreto, la contenida en el art. 20.3 de la citada Ley, que obliga a recabar un informe del Ministerio de Hacienda para la percepción de subvenciones públicas a los entes del sector público integrados en Comunidades Autónomas que no hayan cumplido los objetivos de déficit. El trabajo defiende una interpretación restrictiva del citado precepto sobre la base del análisis del presupuesto de hecho de la norma y su naturaleza de norma sancionadora.