The light olefin product distribution of the methanol-to-olefin (MTO) reaction catalyzed by acid zeolites and zeotypes depends on the nature of the entrapped hydrocarbon pool species that act as co-catalysts. The preferential stabilization by confinement effects of the cationic intermediates involved in the side-chain or paring pathways of the aromatics-based cycle of the MTO mechanism in small-pore cage-based zeolites is determined by the topology of the cavity, and can be quantitatively described through the E int(7/5) parameter obtained from DFT calculations. In this work we extend the study of the E int(7/5) parameter to a wide range of structures (ERI, LEV, AEI, CHA, DDR, AFX, RTH, ITE, SAV, UFI, RHO, KFI, and LTA) and discuss its applicability in small cages with steric constraints to host bulky intermediates, in zeolites with a tight fitting between the cavity and the hosted cations, and in large cages where confinement effects are lost in part and competitive processes occur.

The behavior of single Pt atoms and small Pt clusters was investigated for high‐temperature oxidations. The high stability of these molecular sites in CHA is a key to intrinsic structure–performance descriptions of elemental steps such as O2 dissociation, and subsequent oxidation catalysis. Subtle changes in the atomic structure of Pt are responsible for drastic changes in performance driven by specific gas/metal/support interactions. Whereas single Pt atoms and Pt clusters (> ca. 1 nm) are unable to activate, scramble, and desorb two O2 molecules at moderate T (200 °C), clusters <1 nm do so catalytically, but undergo oxidative fragmentation. Oxidation of alkanes at high T is attributed to stable single Pt atoms, and the C‐H cleavage is inferred to be rate‐determining and less sensitive to changes in metal nuclearity compared to its effect on O2 scrambling. In contrast, when combustion involves CO, catalysis is dominated by metal clusters, not single Pt atoms.