ZrO2 Loading Research Articles

Effect of the SiO2 support on the catalytic performance of Ag/ZrO2/SiO2 catalysts for the single-bed production of butadiene from ethanol

A ternary Ag/ZrO2/SiO2 catalyst system was studied for single-step conversion of ethanol to butadiene by varying the catalyst composition (Ag, Ir, or Pt metal component, Ag/ZrO2 loading, and choice of SiO2 support) and operating conditions (space velocity and feed gas composition). Exceptional catalytic performance was achieved over a 1%Ag/4%ZrO2/SiO2-SBA-16 catalyst leading to 99% conversion and 71% butadiene selectivity while operating under mild conditions (325 °C, 1 atm, and 0.23 h−1). Several classes of silica—silica gels, fumed silicas, mesoporous silicas)—were evaluated as catalyst supports, and SBA-16 was found to be the most promising choice. The SiO2 support was found to significantly influence both conversion and selectivity. A higher SiO2 catalyst surface area facilitates increased Ag dispersion which leads to greater conversion due to the accelerated initial ethanol dehydrogenation reaction step. By independently varying Ag and ZrO2 loading, Ag was found to be the main component that affects ethanol conversion. ZrO2 loading and thus Lewis acid sites concentration was found to have little impact on the ethanol conversion. Butadiene selectivity depends on the concentration of Lewis acid site, which in turn differs depending on the choice of SiO2 support material. We observed a direct relationship between butadiene selectivity and concentration of Lewis acid sites. Butadiene selectivity decreases as the concentration of Lewis acid sites increases, which corresponds to an increase in ethanol dehydration to ethylene and diethyl ether. Additionally, adding H2 to the feed had little effect on conversion while improving catalytic stability; however, selectivity to butadiene decreased. Finally, catalyst regenerability was successfully demonstrated for several cycles.

Synthesis and Characterization of ZrO2 Ceramic Ink for Dispenser Printing

In this study, ZrO2 ceramic ink was formulated for additive manufacturing three dimensional structure using dispenser printing technique. Ceramic ink with various ZrO2 loading (30, 40, 50vol%) was prepared to evaluate their rheological properties and printability. High ZrO2 loading ZrO2 ceramic ink showed higher elastic modulus and improved shape retention, when the ceramic ink was printed and sintered at 1450 °C for 1h. Microstructural analysis of printed ZrO2 objective indicated that high ZrO2 loading objective showed lower porosity and smaller pore size.

Comparison of Phosphate Adsorption onto Zirconium-Modified Bentonites with Different Zirconium Loading Levels

In this study, zirconium-modified bentonites (ZrMBs) with different zirconium loading levels were prepared, and the adsorption behaviors of phosphate on these ZrMBs were comparatively investigated using batch experiments. The results showed that the kinetic process of phosphate on ZrMBs well followed the pseudo-second-second kinetic model. The kinetic process was divided into three stages, including a rapid external surface adsorption stage, a gradual adsorption stage where both the intra-particle diffusion and film diffusion were rate-controlled, and a final equilibrium adsorption stage. The equilibrium adsorption data of phosphate on ZrMBs could be well described by the Langmuir, Freundlich, Sips and Dubinin-Radushkevich isotherm models. Phosphate adsorption onto ZrMBs was more favorable under strongly acidic condition than under weakly acidic or neutral condition, while phosphate adsorption onto ZrMBs under weakly acidic or neutral condition was more favorable than that under alkaline condition. Coexistence of Na+ and K+ slightly enhanced phosphate adsorption onto ZrMBs, while coexisting Ca2+ greatly enhanced the phosphate adsorption. The presence of HCO3- or SO2-4 inhibited the adsorption of phosphate on ZrMBs. The mechanism for phosphate adsorption onto ZrMBs followed the ligand exchange and inner-sphere complexing mechanism. The phosphate adsorption capacity for ZrMB increased with increasing loading level of zirconium, while the amount of phosphate adsorbed on unit mass of ZrO2 in ZrMB decreased with increasing loading amount of zirconium in ZrMB. When the loading amount of ZrO2 in ZrMB increased from 3.61% to 13.15%, the maximum phosphate adsorption capacity (MPAC) for ZrMB increased from 3.83 to 9.03 mg·g-1, while a further increase in the ZrO2 loading amount to 19.63% resulted in a slight increase of MPAC to 9.66 mg·g-1. However, an increase in the loading amount of ZrO2 in ZrMB from 3.61% to 19.63% caused a decrease of the MPAC for the ZrO2 located in ZrMB from 106 to 49.2 mg·g-1. Considering both cost and adsorption capacity of adsorbent, the ZrMB with 13.15% of zirconium loading amount could be more suitably used as an adsorbent to remove phosphate from aqueous solution than the other ZrMBs.

Dry reforming of methane on grafted-supported Rh catalysts: effect of the metal-support interaction on the reaction rate

Catalysts of rhodium supported on pure oxides and modified alumina with 50, 75 and 100% of ZrO2 were prepared by the impregnation method, to be tested in the reaction of dry reforming of methane in order to study the effect of the metal-support interaction on the reaction rate. The catalysts were characterized by N2 adsorption isotherms, CO chemisorption, TEM, temperature programmed reduction, XRD and XPS. The reaction rate for CH4 conversion was measured at 500–700 °C, in the absence of transport limitation. The average Rh cluster size in catalysts with modified supports resulted similar as compared with the catalyst Rh/0%ZrO2–Al2O3, so that the modification of the support had no effect on the dispersion of Rh, which is associated with the similarity in the BET surface area of the pure and modified alumina. The Rh-support interaction is determined by the degree of coverage of alumina with zirconia and by the nature of ZrO2 phase formed in the grafted supports. The higher coverage of alumina with zirconia leads to a lower Rh-support interaction. However, the interaction of Rh with the monoclinic phase seems to be weaker than with the tetragonal phase of zirconia, the latter more abundant as the loading of ZrO2 is increased in the grafted supports. Consequently, the Rh-support interaction increases with the content of ZrO2. Despite the different Rh-support interaction, the structural sensitivity of dry reforming of methane on Rh catalysts was still evidenced, i.e., the DRM reaction rate is mainly determined by the coordination degree of Rh atoms on the catalyst surface.

Synthesis and characterization of electrospun PVdF-HFP/silane-functionalized ZrO2 hybrid nanofiber electrolyte with enhanced optical and electrochemical properties

A facile method to produce a hybrid of organic-inorganic nanofiber electrolyte via electrospinning is hereby presented. The incorporation of functionalized zirconium oxide (ZrO2) nanoparticles into poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) and complexed with lithium trifluoromethanesulfonate (LiCF3SO3) provided an enhanced optical transmissivity and ionic conductivity. The dependence of the nanofiber's morphology, optical and electrochemical properties on the various ZrO2 loading was studied. Results show that while nanofiller content was increased, the diameter of the nanofibers was reduced. The improved bulk ionic conductivity of the nanofiber electrolyte was at 1.96 × 10−5 S cm−1. Owing to the enhanced dispersibility of the 3-(trimethoxysilyl)propyl methacrylate (MPS) functionalized ZrO2, the optical transmissivity of the nanofiber electrolyte was improved significantly. This new nanofiber composite electrolyte membrane with further development has the potential to be next generation electrolyte for energy efficient windows like electrochromic devices.

Enhancing tungsten oxide/SBA-15 catalysts for hydrolysis of cellobiose through doping ZrO2

The number of strong acid sites on a hydrolysis catalyst accessible by the bulky cellulose limits its efficiency in the conversion and utilization of biomass-based resources. In this work, high surface area WZr/SBA-15 catalysts (>400m2/g) were prepared by hydrothermal method and characterized using XRD, N2 adsorption, TEM, Raman, UV–vis, XPS and FTIR of pyridine adsorption. The results showed that doping a moderate amount of ZrO2 into the WO3/SBA-15 catalyst stabilized the tungstate species in the form of a polytungstate species as a result of the strong ZrOx-WOx interaction as well as increased the surface area of the catalyst. The resulting polytungstate species provided strong Brønsted acid sites for hydrolysis. Consequently, the cellobiose conversion was maximized at 5% ZrO2 loading, corresponding to a maximized surface area and density of Brønsted acid sites. This catalytic activity is significantly higher than that of a WO3/ZrO2 catalyst prepared using the conventional impregnation method, indicating the importance of mesoporous structure to the dispersion of active species and to the accessibility of the active sites by the bulky reactant. This result indicates that the density of the strong Brønsted acid sites with improved accessibility by the bulky reactant is essential to achieve a high hydrolysis activity.

CO2-enhanced dehydrogenation of ethane over sonochemically synthesized Cr/clinoptilolite-ZrO2 nanocatalyst: Effects of ultrasound irradiation and ZrO2 loading on catalytic activity and stability

CO2-enhanced oxidative dehydrogenation of ethane was investigated over sonochemically synthesized Cr/clinoptilolite-ZrO2 nanocatalyst with the aim of assessing the effect of composite support and ultrasonic irradiation on the nanocatalyst reactivity and stability. To this aim, ZrO2 promoted clinoptilolite supports varying in zirconia content (0, 25, 50wt%) were synthesized by hydrothermally precipitation method and impregnated with chromium nitrate under ultrasound irradiation. The samples were characterized by XRD, FESEM, EDX, TEM, ICP, BET, FTIR, TPR-H2 and TPD-NH3 techniques. The characterization results indicated that ultrasound irradiation could not only reduce the formation of Cr2O3 and decrease submicron particle size of chromium oxide to nanometer scale, but also promote the distribution of metallic particles and strengthen the chromium-support interaction. As a result, utilizing ultrasound irradiation in the synthesis of Cr/Clinoptilolite helped to maintain a high and stable catalytic activity. These features were more prominent in the presence of zirconia. It was found that the metal oxide nanoparticles with about 4–8nm are dispersed uniformly on the surface of composite support containing 25wt% ZrO2 (CLT-Z25). Moreover, the addition of ZrO2 resulted in the formation of new strong acid sites and a significant modification in the reducibility of chromium species, which alongside homogenous and small Cr nanoparticles account for the superior catalytic performance of ZrO2 containing samples. However, excessive loading of ZrO2 (50wt%) severely covered the surface of clinoptilolite, afforded the aggregations of metallic particles and thereupon, weakened the contact between clinoptilolite and ZrO2, which together with more acid strength seriously resulted in the deactivation of catalyst. In spite of superior initial activity of ZrO2-rich sample among the catalysts tested, ultrasonic synthesized Cr/CLT-Z25 nanocatalyst showed the best catalytic performance after 5h-catalytic reaction.

Catalytic Performance of γ-Al2O3–ZrO2–TiO2–CeO2 Composite Oxide Supported Ni-Based Catalysts for CO2 Methanation

Composite oxide supported Ni-based catalysts were prepared by a wet impregnation technique and applied to the methanation of carbon dioxide. The composite oxide supports were prepared by an impregnation–precipitation method using commercial γ-Al2O3 powder as a host with variation of the percentage of loading of ZrO2, TiO2, and CeO2 promoters from their respective salt precursors. NH4OH was used as the precipitating agent. The as-prepared catalysts were characterized by Brunauer–Emmet–Teller surface area analysis, atomic absorption spectroscopy, X-ray diffraction, temperature-programmed reduction by H2 (H2-TPR), and CO chemisorption. Catalytic activity of the newly synthesized catalysts was investigated toward hydrogenation of CO2 at atmospheric pressure by varying reaction temperature between 250 and 400 °C (with increasing step equal to 25 °C). Experimental results revealed that the composite oxide supported Ni-based catalysts showed performance superior to that of the γ-Al2O3 only supported Ni-based cat...

Carbon-Supported Zirconium Oxide as a Cathode for Microbial Fuel Cell Applications.

Cost-effective electrode materials to be used as cathodes in lab-scale prototype microbial fuel cells (MFCs) were prepared from mixtures of carbon black (C) and zirconium oxide (ZrO2 ) of different composition. The catalytic activity of these cathodes in the oxygen reduction reaction (ORR) and their stability toward poisoning in typical MFC operative conditions were assessed by using electrochemical techniques. Scanning electron microscopy and Brunauer-Emmett-Teller measurements gave insights into sample morphology and surface area. The results indicated that the C/ZrO2 sample with a ZrO2 loading of 25 wt % (C/ZrO2 _25) represents the best compromise in terms of ORR activity and stability. C/ZrO2 _25 was assembled into cathodes of a prototype single-chamber MFC, which produced a maximum power density of 600 mW m-2 . A comparative cost analysis of energy production indicated that the cost of energy delivered by MFCs assembled with a C/ZrO2 cathode was more than 15 times lower than that of MFCs assembled with a reference Pt/C cathode.

Vapor phase esterification of levulinic acid over ZrO2/SBA-15 catalyst

ZrO2/SBA-15 catalysts with different ZrO2 loadings prepared by impregnation method were tested for the esterification of levulinic acid in a fixed-bed reactor in vapor phase conditions at atmospheric pressure for the first time and found that the catalyst with 7 weight percent ZrO2 exhibited 100% conversion of levulinic acid and 96% selectivity to methyl levulinate due to the presence of more number of moderate acidic sites. It is interesting to observe the formation of γ-valerolactone as the alcohol chain length increases at the expense of alkyl levulinate, through MPV reduction mechanism.

Effect of ZrO2 on the catalytic performance of nano γ-Al2O3 in dehydration of methanol to dimethyl ether at relatively low temperature

A series of ZrO2/γ-Al2O3 catalysts were prepared by incipient wetness impregnation of zirconyl nitrate hydrate aqueous solutions on nano-γ-Al2O3 with ZrO2 loadings (1–30 % w/w) and calcined at 450 and 550 °C for 3 h in a static air atmosphere. Physicochemical properties of the catalysts were determined using TG, DTA, XRD, FT-IR, Raman spectroscopy, TEM, and N2 sorption measurements. The surface acidity of the catalysts was investigated by dehydration of isopropanol and adsorption of pyridine, 2,6-dimethyl pyridine and TPD–pyridine. This series of catalysts was used for vapor-phase dehydration of methanol to dimethyl ether in a fixed bed reactor. It was found that all catalysts in this study were active and selective for DME synthesis. According to the experimental results, 1 % ZA catalyst exhibited the highest activity with selectivity of 100 % toward DME.

Catalytically Upgrading Bio-oil via Esterification

Sulfated ZrO2–TiO2 mixed oxides with different loading ratios were synthesized using a deposition precipitation approach. All catalysts were characterized by Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), infrared spectroscopy (IR), energy-dispersive X-ray (EDX) analysis, and transmission electron microscopy (TEM), and the activities for esterification were compared using acetic acid and ethanol as the model reaction. A total of 93.7% acetic acid was converted into ester when 50 wt % ZrO2 loading catalyst was applied at 100 °C. The characterizations of original and upgraded bio-oil via esterification by applying sulfated 50 wt % ZrO2–TiO2 loading ratio catalyst were investigated. After upgrading, fuel properties of pyrolysis oil improved. Acetic acid peak area percentage dropped remarkably from 15.87 to 0.774%, indicating that the properties of bio-oil were enhanced by SO42–/ZrO2–TiO2 catalytic esterification. Because of ethanol addition, the water content in bio-oil decreased from 40 to 16.9% and...

Synthesis, Characterization, and Application of Exfoliated Graphite/Zirconium Nanocomposite Electrode for the Photoelectrochemical Degradation of Organic Dye in Water

We report the synthesis and application of a novel exfoliated graphite–zirconium oxide nanocomposite photoanode for the photoelectrochemical degradation of eosin yellowish dye in water. Zirconium oxide nanoparticle was synthesized by sol–gel, method and EG–ZrO2 nanocomposite was synthesized by wet solution method. The materials were characterized by scanning electron microscopy, thermogravimetry and differential thermal analysis (TGA-DTA), Brunauer–Emmett–Teller (BET) surface area analysis, and X-ray diffraction (XRD). Applicability of the EG–ZrO2 as photoanode material was investigated by the photoelectrochemical degradation of eosin yellow as a model for organic pollutants in 0.1 M Na2SO4 (pH 7) solution at a current density of 5 mA cm−2 after optimizing the EG–ZrO2 loading. The FTIR, XRD, and Raman data showed the formation of the nanocomposite. The XRD patterns show that the ZrO2 nanoparticle contains mainly the monoclinic phase as complemented by Raman spectroscopy. Photoelectrochemical studies with the EG–ZrO2 nanocomposite showed a significant decrease in the initial dye concentration (20 ppm) compared with the bare exfoliated graphite (EG) and zirconium oxide (ZrO2) only. The results indicate that the ZrO2 nanoparticle in the EG–ZrO2 composite enhanced the degradation efficiency of the EG substrate. Thus, EG–ZrO2 composite can be used for the photoelectrochemical oxidation of organic pollutants, especially organic dyes.

3-D flower like Ce–Zr–Cu mixed oxide systems in the CO preferential oxidation (CO-PROX): Effect of catalyst composition

Ce–Zr–Cu mixed oxide systems, with different contents of ZrO2 and CuO, were prepared by slow co-precipitation method, leading to the formation of materials with a flower-like morphology. It was evaluated both the role of CuO loading (3–7wt%), by maintaining constant the amount of ZrO2 (7wt%), and the role of ZrO2 (2–10wt%) with a fixed amount of CuO (7wt%). The prepared catalysts were characterized by means of ICP-OES, SEM, N2 physisorption, quantitative XRD, H2-TPR, and XPS. Their catalytic performances in the preferential oxidation of CO in excess of H2 (CO-PROX) were evaluated, in the 40–190°C temperature range. Characterization and catalytic results showed that an optimum Zr/Ce molar ratio and CuO loading are required to attain the best catalytic performance over the studied nanostructured Ce/Zr/Cu oxide system. Characterization results revealed that, regardless of the sample composition, all of them presented similar flower-like morphology and textural properties. Instead, the catalyst composition determined the crystalline phases formed, their reducibility and surface distribution. The catalyst containing an intermediate ZrO2 loading (7wt%) and the highest studied CuO amount (7wt%), FCZCu77, showed the higher fraction of undetectable CuO from XRD, that is the highest proportion of highly dispersed Cu species also observed from H2-TPR. These characteristics justify how FCZCu77 catalyst exhibited a quite higher catalytic activity than the others samples.

Effective synthesis of novel O-acetylated compounds over ZrO2-Al2O3 solid acid

The solid acids such as ZrO2, Al2O3 and ZrO2-Al2O3 containing different ZrO2 loadings (10–80mol%) were prepared by solution combustion method (SCM) and characterized for their total surface acidity by NH3-TPD/n-butylamine back titration method and crystallinity by powder X-ray diffraction (PXRD) technique. These solid acids were evaluated for their catalytic activity in the synthesis of novel O-acetylated products from substituted phenols, pyridine alcohols and aryl alcohols with acetic anhydride (AA) as an acetylating agent. The reaction conditions were optimized by varying the catalyst, molar ratio of the reactants, reaction temperature and amount of the catalyst. All the solid acids used in this study exhibited good catalytic activity in the reaction. In particular, ZrO2-Al2O3 containing 80mol% of ZrO2 was found to be highly active in the acetylation reaction with high yield of acetylated products. Triangular correlation between the surface acidity, crystallinity and catalytic activity of solid acids was observed. These solid acids were found to be reactivable and reusable.

Synthesis, characterization and optimization of photocatalytic activity of TiO2/ZrO2 nanocomposite heterostructures

a b s t r a c t Titanium dioxide/zirconium dioxide nanocomposites were synthesized using a simple and modified sol–gel method. The synthesized particles were characterized through SEM, TEM, XRD, and DTA/TGA. SEM analysis shows micrographs with irregular and sharp edged particles. TEM analysis shows spherical particles of average diameter 10.5 nm. Tetragonal structure of TiO2/ZrO2 nanocomposite particles with stabilized anatase phase was confirmed by XRD studies. The average crystallite size was calculated from XRD, using Scherrer’s formula. Band gap was calculated from the DRS spectra using Kubelka-Munk function and Photoluminescence (PL) was done to study the recombination rate of charge carriers. Results showed a considerable increase in band gap on ZrO2 addition and subsequent decrease in recombination rate. Impedance study showed a significant decrease in dielectric characteristics on ZrO2 addition. Photocatalytic activity of the synthesized catalysts was studied by degradation of an azo-dye, Ponceau BS, using ultra-violet source of light. Optimum activity was observed on 6.0% ZrO2 loading. © 2014 Elsevier B.V. All rights reserved.

Pore Structure Model of Bimodal Catalyst Supports

Co/ZrO2–SiO2 bimodal catalyst has higher activity and higher selectivity for the Fischer-Tropsch synthesis than conventional catalysts. This study investigated the catalyst support pore structure in detail, especially the formation of small pores with a model analysis. The analysis considered 10 wt% ZrO2–SiO2 and 20 wt% ZrO2–SiO2 bimodal catalyst supports with various loadings of ZrO2. Higher loadings of ZrO2 from 10 to 20 wt% decreased the large pore size from 59.8 to 56.7 nm, resulting in the promotion of the formation of small ZrO2 pores inside the large SiO2 pores. Interestingly, small pore size remained unchanged at 3.9 nm, irrespective of the ZrO2 loading, indicating that the small pore size was determined by the character of the ZrO2 nanoparticles participating in the self-assembly of ZrO2 nanoparticles inside the large SiO2 pores. A theoretical model of the agglutination of ZrO2 nanoparticles was established, and used to analyze the formation of small ZrO2 pores. The model suggested that 12 ZrO2 nanoparticles formed a unit cell with diamond lattice structure. The obtained small pore size and large pore size were very close to the experimental findings, and the calculated specific surface area and pore volume were also similar to the measured values.

Sonochemical synthesis of NiMo/Al2O3–ZrO2 nanocatalyst: Effect of sonication and zirconia loading on catalytic properties and performance in hydrodesulfurization reaction

In order to elucidate the effect of support composition and preparation method on catalytic properties and hydrodesulfurization activity, a series of NiMo/Al2O3–ZrO2 nanocatalysts with various ZrO2 contents were synthesized by using impregnation and sonochemical methods. The samples were characterized by using BET, XRD, FESEM, PSD, EDX and FTIR techniques. The results indicated that in the samples with low ZrO2 contents, zirconia particles existed as amorphous phase which confirmed the existence of stronger interaction between metal oxides. The nanocatalyst synthesized by sonochemical method resulted in smaller particles with more uniform distribution compared to impregnation method. The catalytic activity of synthesized nanocatalysts was measured in a stirred slurry-tank reactor at atmospheric pressure and 160°C using thiophene as the sulfur containing model compound. The catalytic activity of the sonochemically synthesized nanocatalysts was higher than those synthesized by impregnation method. ZrO2 loading led to a catalyst with higher activity compared to the zirconia free catalyst. Maximum catalytic activity was obtained with the zirconia content of 15wt.%. Further introduction of zirconia led to a decrease in catalytic activity due to the formation of large ensembles on nanocatalyst surface. Furthermore, this work suggested a reaction path to reveal the mechanism of thiophene hydrodesulfurization over NiMo/Al2O3–ZrO2 nanocatalyst.

Synthesis of PVDF-co-HFP-ZrO<sub>2</sub> Based Composite Polymer Electrolyte for Battery Applications

Composite polymer electrolytes based on poly (vinilydene fluoride-co-hexafluoro propylene) as polymer host, zinc triflate as dopant salt and ZrO2 as nanofiller were prepared by solution casting technique using N,N dimethylformamide (DMF) as solvent. The loading of the ZrO2 nanofiller carried out for the optimized composition shows an increasing trend of electrical conductivity from 10-11 to 10-5 Scm-1 at 298 K. The effective structural complexation of the polymer electrolyte system and influence of nanofiller were also analyzed by means of Fourier transform infrared spectral analysis. The detailed impacts on the degree of crystallinity were investigated by differential scanning calorimetric analysis. The electrochemical stability of the optimized composition with 7 wt% ZrO2 loading was found to exist up to 2.6 V.

Enhanced hydrogen generation using ZrO2-modified coupled ZnO/TiO2 nanocomposites in the absence of noble metal co-catalyst

Mesoporous ZrO2-modified coupled ZnO/TiO2 nanocomposites were prepared by a surfactant assisted sol–gel method. The photocatalytic performance of these materials was investigated for H2 evolution without noble metal co-catalyst using aqueous methanol media under AM1.5 simulated light. The H2 evolution was compared with coupled ZnO/TiO2, TiO2, ZnO and Degussa P25. The ZrO2-modified nanocomposites exhibited higher H2 generation, specifically 0.5 wt.% ZrO2 loading produced 30.78 mmol H2 g−1 compared to 3.55 mmol H2 g−1 obtained with coupled ZnO/TiO2. A multiple absorbance thresholds at 435 nm and 417 nm were observed with 0.5 wt.% ZrO2 loading, corresponding to 2.85 eV and 2.97 eV band gap energies. The high surface area, large pore volume, uniform crystallite sizes and enhanced light harvesting observed in ZrO2-modified nanocomposites were contributing factors for effective charge separation and higher H2 production. The possible mechanism of H2 generation from aqueous methanol solution over ZrO2-modified nanocomposite is presented.