Catalytic hydroliquefaction of rice straw for bio-oil production using Ni/CeO 2 catalysts

Advances in porous and nanoscale catalysts for viable biomass conversion

“…25b). The significance of oxygen vacancies in biomass valorization is also noticed over other metal oxides, such as TiO 2 and ZrO 2 , 274 MoO 3 , 275 CeO 2 , 276 and CeO 2 -ZrO 2 . 277 An added benefit of oxygen vacancies is their mild acidic strength that can direct a specific reaction pathway towards the formation of desirable bio-based chemicals.…”

“…The importance of these shape-controlled ceria supports is evident in various biomass upgrading reactions, such as production of acrylic acid from glycerol, 292 oxidative transformation of 1,3-propanediol into methyl esters 293 and hydroprocessing of rice straw biomass. 276 Heterogeneity of particle size distribution is a key concern of conventionally synthesized supported metal catalysts, which not only adversely affects the atom efficiency, but also enables unwanted side reactions. 245,246,248,298,299 Uniquely identifying and controlling the location of active metal centers is also quite difficult in conventional supported metal catalysts, however it is essential to promote a specific reaction pathway towards desirable chemicals.…”

“…Ni nanoparticles dispersed on CeO 2 nanorods, synthesized by a one-pot hydrothermal method, exhibited good catalytic activity in hydroprocessing of rice straw biomass. 276 Shape-controlled CeO 2 nanorods preferentially expose a large fraction of reactive (110) and (100) crystal planes, which can provide a high concentration of redox active sites. 269,307 Ni/CeO 2 catalyst with a Ni/Ce molar ratio of 2/10 afforded 89% conversion of rice straw and 66.7% yield of bio-oil, which was attributed to homogeneous dispersion of Ni metal sites and abundant oxygen vacancies in cerium oxide.…”

“…269,307 Ni/CeO 2 catalyst with a Ni/Ce molar ratio of 2/10 afforded 89% conversion of rice straw and 66.7% yield of bio-oil, which was attributed to homogeneous dispersion of Ni metal sites and abundant oxygen vacancies in cerium oxide. 276 Biomass to MoO 3 mass ratio played a pivotal role on the deoxygenation activity of MoO 3 /TiO 2 and MoO 3 /ZrO 2 catalysts (10 wt% MoO 3 loading) for catalytic fast pyrolysis of pine biomass. 56 Owing to adequate amounts of surface reduced Mo species (Mo 3+ and Mo 5+ ), the supported MoO 3 catalysts converted approx.…”

Effect of decomposition of catalyst precursor on Ni/CeO2 activity for CO methanation

“…The peaks can be labeled v0, v, v′, v″, and v′″, which correspond to Ce 3d5/2, and u0, u, u′, u″, and u′″, which correspond to Ce 3d3/2. The four peaks v0, u0, u′, and v′ are indexed as Ce 3+ , and the other six peaks are attributed to Ce 4+ [36,44,45]. The Ce 3+ content (%) is calculated from the areas of u′ and v′ according to the following equation [45,46]:…”