Table 1. Selective Hydrogenation of 4-Nitrostyrene over Different Au Catalysts^a.

			sel./%c
entry	catalystsb	con./%c	1	2	3
1	NiAlO-2-500	0.3	58.2	25.9	15.9
2	0.43% Au/NiAlO-2-500	98.4	98.1	0.2	1.7
3	0.38% Au/NiAlO-2-500-SD	29.4	95.0	1.5	3.5
4	0.15% Au/NiAlO-2-500	18.9	82.9	16.2	2.9
5	0.68% Au/NiAlO-2-500	98.1	94.6	0.3	5.1
6	0.38% Au/NiAlO-3-500	40.5	63.6	35.3	1.1
7	0.44% Au/NiAlO-4-500	74.8	2.0	94.5	3.5

^aReaction conditions: p(H₂) = 1.0 MPa; T = 100 °C; catalyst 0.1 g; 4-nitrostyrene 100 μL; toluene 5 mL; stirring speed = 500 rpm; and reaction time 4 h.

^bThe molar ratio of Ni to Al and the Au actual loading were determined by ICP–AES.

^cThe conversion of 4-nitrostyrene and selectivity toward the products were determined by gas chromatography (GC) and GC–mass spectrometry (MS). No other byproducts were observed, and the carbon mass balance of about 96% was obtained by using o-xylene as an internal standard.