A highly
efficient and recyclable catalyst, cerium-immobilized
silicotungstic acid nanoparticle-impregnated zirconia (Ce@STANPs/ZrO
2
), has been synthesized. The catalytic activity of Ce@STANPs/ZrO
2
was investigated for the first time in multicomponent synthesis
of isatin-based imidazoles under microwave irradiation in water. Ce@STANPs/ZrO
2
was used for C=O bond activation in overall reaction
to synthesize isatin-based imidazoles. The structure of catalyst was
confirmed by characterization techniques, such as Fourier transform
infrared (FTIR), scanning electron microscopy (SEM)/energy dispersive
X-ray, elemental mapping, transmission electron microscopy, ζ-potential
and diffraction light scattering, X-ray diffraction (XRD), thermogravimetric
analysis, temperature-programmed desorption-NH
3
, electron
paramagnetic resonance (EPR), and inductively coupled plasma atomic
emission spectroscopy (ICP-AES) analyses. The recovered catalyst was
found to be efficient up to seventh cycle and was confirmed by FTIR,
SEM, XRD, EPR, and ICP-AES analyses. The advantages of the present
protocol are recyclability of catalyst, green reaction conditions,
excellent yield (94%) of the products, shorter reaction time period
(5–7 min), and clean reaction profile.