Uniformly-Dispersed Ni Nanoparticles Combined With Titanium Oxides As Efficient Catalysts Towards Hydrogen Generation From Cellulose Under Mild Conditions

Producing hydrogen, which is the ideal clean energy, from biomass has extremely practical application value. Presently, many of the methods to produce hydrogen from biomass require high temperature and pressure to break down biomass. Therefore, it is urgent necessary to develop new generations of efficient catalysts. In order to achieve the purpose of hydrogen production from biomass under mild conditions, this work creates uniformly-dispersed Ni nanoparticles combined with titanium oxides, for which photocatalysis-assisted aqueous-phase reforming could be expected, as efficient catalysts towards hydrogen generation from cellulose. The results are as follows:(1) The uniformly-dispersed Ni nanoparticles combined with titanium dioxide catalysts are prepared from the Ni-Ti layered double-hydroxide compound precursor. The hydrogen production was achieved under a reaction temperature as low as180℃, affording a H2production efficiency of31.6 mmol/gcellulose/gcatalyst, better than that reported in former literature under260℃(17.8mmol/gcellulose/gcatalyst).(2) The synergistic effect between Ni and titanium dioxide are proved by contrast experiments. The hydrogen production is enhanced by the synergistic of aqueous-phase reforming with photocatalytic, and electronic effect between Ni and titanium dioxide.(3) Regulating the size of Ni nanoparticles, the activity increases with particle size decreasing. Regulating the crystalline phase composition of TiO2, the contribution of photocatalysis reaches extreme value when phase ratio approaches the phase composition of P25.(4) Changing the titanium oxides into Ni2TiO4-NiTiO3,11.2mmol/gcellulose/gcatalyst hydrogen could be obtained over Ni-Ni2TiO4-NiTiO3catalyst. After using five times,10.0mmol/gcellulose/gcatalyst hydrogen still could be achieved.