First, we tested all the prepared Ni@C catalysts and other commercially available catalysts Ru/C, Pd/C, and Raney nickel for the hydrogenation of acetophenone in a cheap, non-toxic ethanol solvent and H2 atmosphere for 15 h. Figure shows the distribution of phenethyl alcohol on catalysts with different yields and selectivities. As mentioned above, the oxidation step significantly affects the physical properties of the catalyst. Considering the comprehensive conversion rate and selectivity, the catalysts A, B prepared by the oxidation step perform better than the corresponding catalysts D, E, C without the oxidation step. When the pyrolysis temperature of the unoxidized catalyst rises from 600 to 700 degrees Celsius, the catalyst activity has a significant decrease, while the catalyst activity after oxidation is less affected by the pyrolysis temperature. At a pyrolysis temperature of 700 degrees, the solvent used to prepare the catalyst also affects the catalytic activity and product selective activity. The catalyst E prepared from EtOH generally has worse reactivity and selectivity than the corresponding catalyst C, D prepared from H2O. Among all Ni-based catalysts encapsulated by thin graphene layers, the catalyst F Ni/NiO@-700-200-1-H2O showed the best overall conversion and selectivity, which were 100% and 98.31%, respectively. Ni@C-700-EtOH showed the worst reactivity. The catalytic activity of other commercially available noble metal catalysts Ru/C, Pd/C, and Raney nickel is not satisfactory. The noble metal catalysts Ru/C and Pd/C did not produce the target product, while Raney nickel showed good catalytic activity but with poor selectivity. In order to highlight the advantages of flow reactor over batch reactors, herein, we choose the prepared catalyst Ni@C-700-EtOH to conduct acetophenone hydrogenation experiments to screen the flow reactor process conditions. Conversion and selectivity were determined by GC using 1, 3, 5-trimethoxybenzenen as an internal standard. The types of products were confirmed by GC