Role of Precursor Concentration for the Cu Incorporation in SAPO-34 Frameworks

In order to utilize Cu(II) as a catalytic site for deNOx-processes, the Cu(II) active sites must be protected from autoreduction and aggregation. Incorporating Cu(II) into the microporous framework of SAPO-34 has been shown to yield single site Cu(II), which are protected from autoreduction and aggregation. The incorporation process in the micropores can happen when Cu replaces either Al, P, or Si in the SAPO-34 framework. Changes in the Al, P, or Si-content before the crystallization step could therefore offer new ways in which Cu is incorporated, which could lead to changes in the catalytic activity as well. Preliminary activity measurements has revealed that changing the Si content radically changed the activity and selectivity of the catalysts. Monitoring the local environment of the Cu(II) active sites in-situ could therefore reveal exactly why these changes in catalytic activity occur when we change the precursor concentration in the synthesis of SAPO-34.