2,4-dinitrophenylhydrazanomethylphenol (DNPHMP) was immobilized onto silicate rice husk ash to form a heterogeneous catalyst denoted as RHDNPH. The elemental and EDX analysis of RHDNPH showed the nitrogen is incorporated into silica. The RHDNPH had 154.6 m2g-1 as a specific surface area. The FT-IR clearly showed the appearance of –NH and C=N absorption band at the […]