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[Display omitted] • Mg incorporated into zeolite Beta framework by two-step postsynthesis procedure. • Rh3+/[MgO 4 ]2- electrostatic interactions stabilize single Rh atoms. • Catalytic efficiency of Rh/Mg-Beta due to low atomic coordination and basicity. • High selectivity in phenol hydrogenation to cyclohexanone at mild conditions. Nanoparticles are of interest in heterogeneous catalysis because of their excellent activity associated with atoms in a low coordination environment. However, their high reactivity becomes a drawback where selectivity is desired, compounded by their propensity towards agglomeration. Here, we show that stable subnanometric Rh particles can be prepared in a Mg-doped zeolite Beta based on the electrostatic interaction of the negatively charged zeolitic framework and the Rh3+ precursor. The Mg ions are incorporated into the zeolite framework whereas the Rh is located in the channels adjacent to the Mg. With only 0.27 and 0.5 wt% Mg and Rh, respectively, the Rh/Mg-Beta catalysts were highly active with > 94 % selectivity for the hydrogenation of phenol to cyclohexanone, an important intermediate for the production of Nylon. Key to the selectivity is the formation of the C=O double bond early in the reaction sequence, aided by the basicity of the Mg-Beta support. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zr-HY is an excellent catalyst for the cascade reaction. • Hydrophobicity and cosolvents significantly accelerate the title reaction. • Ratio of open:closed Zr sites higher in Zr-HY than Zr-Beta. • IR of sorbed 2-pentanol probes hydrophobic/hydrophilic environment. Trans -anethole is an important ingredient in many flavors, fragrances and pharmaceutical formulations. Heterogeneous catalysis provides the opportunity for its green synthesis from 4′-methoxypropiophenone via a cascade of Meerwein-Ponndorf-Verley reduction followed by dehydration. Zr-containing zeolites were especially active catalysts. Surprisingly, Zr-HY was more active than Zr-Beta or mesoporous Zr-MSU. The effect of pore size, hydrophobicity and co-solvent has been investigated. Pyridine poisoning revealed that weak Lewis acid sites can catalyze the MPV reduction but stronger acid sites are required for the dehydration. The hydrophobicity and the ratio of open/closed Zr sites were higher for Zr-HY than Zr-Beta. Adding a moderately polar co-solvent like p -xylene more than doubled the reaction rate compared to only 2-pentanol as solvent. For an efficient cascade reaction, a hydrophobic catalyst with large micropores is required which combines hydrogen transfer and dehydration activities, together with an inert co-solvent that balances the concentration of both substrates inside the zeolite. [ABSTRACT FROM AUTHOR]