2) The nucleophilic sites on the catalyst prefer the adsorption of NO2 group while repel the C=C bonds, due to the different electronic property of electron-rich C=C bonds and electron-deficient NO2 groups ; 3) The sensitive hydrogenation of double C=C bond to the catalyst structure instead of the -NO2 functional group. Following on from the above-mentioned findings, the noble metal catalysts like Ru, Pd, Pt, and Au usually have high hydrogenation ability and they were predominant traditionally and had been studied widely for achieving selective reduction a long time. In 2006, Corma and Serna first reported the Au-based catalysts in the reduction of 3-nitrostyrene, excellent reactivity (98.5% con.) and selectivity (95.9%) were obtained using the Au/TiO2 catalysts. Since then, many researchers have developed efficient noble metal-based catalysts for the chemo-selective hydrogenation of 3(4)-vinylaniline. Recently, Song et.al synthesized Au-melamine colloidal spheres by directly heating an aqueous solution of Au 3+ and melamine at 70 °C . Then in the mixed solution containing colloidal sphere and poly(sodium-p-styrenesulfonate)(PTS), they rapidly added a great amount of NaBH4 and obtained multi-shell Au with modification of reducing PTS in situ. The prepared surface-modified with more shell number catalyst S-PTSAu displayed excellent reactivity (>99%) and selectivity (97%) in the NH3• BH3 initiated selective hydrogenation of 4-nitrostyrene under light condition (Xe lamp at 0.5 Wcm -2 with 420 nm cutoff filter at 25 °C), compared with unmodified Au and other Au catalysts with less shell number. While in this reaction, like many other selective reduction processes in the industry, a large amount of reducing agents such as 2.5 equiv. NH3• BH3 in this case, sodium hydrosulphite , samarium iodide , stannous chloride is still typically used, and it normally generate huge amounts of waste. Compared with other reducing agents or other hydrogen donors, molecular H2 is cheaper, readily available, and also environmentally benign. With the use of molecular H2, Zhang et. al. reported a rationally designed highly active and chemo-selective FeOx-supported Pt catalyst for hydrogenation of substituted nitroarenes . They also found that the hydrogenation of other unsaturated functional groups was unavoidable when the reaction time was prolonged and/or the temperature was raised. Later, using a ZnAl-hydrotalcite supported thiolated Au nanoclusters as a precatalyst, they obtained the well-tuned sized Au nanocatalysts that were only highly active for the -NO2 group but inert with respect to the C=C bond, resulting in the excellent reactivity (100% con.) and outstanding selectivity (>98%) of 3-VA in wide reaction period and temperature windows . Recently, the Hutchings group described a synthesis method of a low metal loading Pt/TiO2 catalyst through careful manipulation of the post-synthetic heat treatment procedure including calcination and subsequent reduction, together with control over the metal loading, thereby preventing any TiOx coverage of the Pt active sites. The prepared Pt/TiO2 catalyst showed 99% conversion and 90% 3-VA selectivity in the hydrogenation of 3-nitrostyrene. Although there exist many advanced efficient noble metal-based catalysts for chemo-selective hydrogenation, the current trend in the pharmaceutical and agrochemical industries is the advancement of economical, green, and environmentally friendlier processes. Since the high cost and scarcity of noble metal, it is important and highly desirable to develop more cost-effective and practical application methodologies .