Zen Maeno

The study of the formation, characterization, and functionality of isolated surface hydrides on solid materials is a formidable task because of the complexity of solid surfaces and the difficulty of analyzing structures in solids. Herein, we found the formation of indium (In) hydride species supported by CHA zeolites. The In hydrides were formed by treatment of an In-exchanged CHA zeolite (In-CHA) with H₂ at high temperatures (>773 K). <i>In situ</i> Fourier transform infrared (FTIR)

The capture of CO2 and its reduction with H2 to form C1 compounds (i.e., CO2 capture and reduction; CCR), such as CO and CH4, using dual-functional materials (DFMs) has recently attracted attention as a promising process for CO2 emission reduction and utilization. Although CO is more useful than CH4 from a chemical synthesis perspective, the development of an effective DFM system to generate CO has been explored much less than that for CH4 generation. This study successfully developed Na-promote

Atomic dispersion of metal species has attracted attention as a unique phenomenon that affects adsorption properties and catalytic activities and that can be used to design so-called single atom materials. In this work, we describe atomic dispersion of bulk Pd into small pores of CHA zeolites. Under 4% NO flow at 600 °C, bulk Pd metal on the outside of CHA zeolites effectively disperses, affording Pd²⁺ cations on Al sites with concomitant formation of N₂O, as revealed by mi

We have carried out an experimental and theoretical study of CHA-zeolite supported indium (In)-oxo clusters that promote CH4 activation at room temperature. X-ray absorption fine structure (XAFS) measurements indicate the formation of multinuclear In-oxo clusters by the O2 activation of the In(i)-exchanged CHA zeolite prepared through reductive solid-state ion exchange (RSSIE). The structure of the In-oxo clusters and their locations were investigated in detail using ab initio thermodynamic anal

In this study, we successfully developed nickel (Ni)-modified tungstate zirconia (Ni/WO3/ZrO2) as an effective material for chemical looping dry reforming of methane (CL-DRM) under isothermal conditions (750 °C). The performance of Ni/WO3/ZrO2 strongly depended on the WO3 loading amount. The optimal amount of 10.0 wt% WO3, corresponding to low surface W density (<4 W atoms/nm2), in Ni/WO3(10)/ZrO2 resulted in the exclusive formation of dispersed tungstate species, such as isolated monotungstate

In this study, the characterization of In-exchanged CHA zeolite (In-CHA (SiO2/Al2O3 = 22.3)) was conducted by in-situ X-ray diffraction (XRD) and ammonia temperature-programmed desorption (NH3-TPD). We also prepared other In-exchanged zeolites with different zeolite structures (In-MFI (SiO2/Al2O3 = 22.3), In-MOR (SiO2/Al2O3 = 20), and In-BEA (SiO2/Al2O3 = 25)) and different SiO2/Al2O3 ratios (In-CHA(Al-rich) (SiO2/Al2O3 = 13.7)). Their catalytic activities in nonoxidative ethane dehydrogenation