Increasing O2 Concentration Research Articles

Effects of increased O3 concentration on growth, subcellular structure and reactive oxygen metabolism of turf-type Festuca arundinace

Taking ambient environmental O3(40 nmol·mol-1) as control, the study was conducted to assess the impact of elevated O3(80 and 160 nmol·mol-1) on the growth, subcellular structure and reactive oxygen metabolism of turf-type Festuca arundinace in open top-chambers (OTCs). The results showed that under 14-day fumigation, the height and leaf width of F. arundinace decreased significantly, and the total biomass decreased by 43.7%, and some fully expanded leaves yellowed under 80 nmol·mol-1 O3. Some visible injury symptoms, brown spots and necrosis appeared in the leaves, the total biomass decreased by 46.2%, and plasma membrane became loose from the cell wall and convoluted, chloroplast and mitochondria were damaged under 160 nmol·mol-1 O3. The rate of superoxide anion (O2-·) production, hydrogen peroxide (H2O2) content, malonaldehyde (MDA) content and the activities of antioxidant enzymes were higher under the increasing O3 concentrations (80 and 160 nmol·mol-1) compared with control. Total phenolics and the antioxidant capacity increased at first and then decreased with the rise of O3 concentration. It indicated that O3 has already affected F. arundinace growth and antioxidative metabolism before visible injury symptom appeared. F. arundinace had an adaptive response to elevated O3, but it could not protect itself from excessive O3 or long-term O3 exposure.

Will the shift from crude oil to natural gas burning for power generation at an oil refinery increase ozone concentrations in the region of Cubatão (SE-Brazil)?

The ozone (O3) hypersensitive species Nicotiana tabacum Bel W3 was used to assess the impact on O3 contamination profile by a natural gas-powered thermoelectric plant (TP) that provides power to an oil refinery at Cubatão (SE-Brazil). An increase in O3 levels would represent an even more harmful effect to the Atlantic Rainforest present in the region. The biomonitoring study was performed along TP pre-operation, transition and TP post-operation phases. Tobacco plants were biweekly exposed at urban, industrial and forest areas at different altitudes. O3-induced leaf injuries were evaluated at the end of each exposure. N. tabacum plants at forest sites at mountain slope were usually more affected by O3, especially at higher layers. As TP started operating, nitrogen dioxide (O3 precursor) mean concentrations increased considerably (6ppb to 16ppb). The contamination of the Atlantic Rainforest by high levels of N created a favourable scenario for an increase in O3 concentrations. In fact, F200, F300 and F350 sites (forest sites at 200, 300 and 350m.a.s.l.) had plants showing a significant increase in O3-induced leaf injuries. Phytotoxic levels were similar to those found at F700 site (forest site at 700m.a.s.l.), which were high for the whole study period. The new O3 contamination profile persisted for F200 and F300 sites during TP post-operation phase. Although slightly lower levels than those seen on transition phase, the intensity of O3-injuries remained higher compared to the original conditions. The use of Nicotiana tabacum Bel W3 allowed to see the negative impact on the air quality after TP started operating, contributing to an increase in O3 concentrations and phytotoxic levels at forest sites at mountain slope. Plant community were then exposed to an even higher harmful effect compared to the first phase. The stability and fitness of the Atlantic Rainforest influenced by the pollution coming from Cubatão are still under potential risk. However, how the vegetation will behave at this new scenario is unknown and requires time.

Influence of operating parameters on arsenic transformation during municipal sewage sludge incineration with cotton stalk

Addition of cotton stalk (CS) has been proved to promote dramatically the transformation of toxic As3+ to less toxic As5+ in the fly ash during municipal sewage sludge (MSS) incineration. However, the fate of arsenic during co-firing of MSS and CS in different operating parameters was still unclear. In the present study, the effects of incineration temperatures and O2 content in the flue gas on speciation transformation of arsenic during MSS and 70% MSS/30% CS incineration were investigated in a bubbling fluidized bed. The results show that less arsenic is distributed in bottom ash whereas more arsenic is migrated to the fly ash and flue gas, with the temperature increasing from 800 °C to 950 °C. The arsenic capture in fly ash is facilitated predominantly by the condensation and/or physical adsorption of As2O3(g) at the temperatures from 800 °C to 900 °C. The chemical oxidation of As2O3(g) is favored by forming various arsenates (As5+) at 950 °C. At low O2 content from 1% to 5%, some arsenic compounds in MSS such as As2S3 can react with O2 to produce As2O3(g), and then more As2O3(g) is captured in the fly ash by the inherent mineral compounds like CaO through the condensation and/or physical adsorption. Further increasing O2 content especially to 9% stimulates significantly the oxidation of As3+ to As5+ in the fly ash, which is mainly attributed to the chemical reactions between As2O3(g), various mineral compounds and sufficient O2.

Co-combustion of sewage sludge and coffee grounds under increased O2/CO2 atmospheres: Thermodynamic characteristics, kinetics and artificial neural network modeling

(Co-)combustion characteristics of sewage sludge (SS), coffee grounds (CG) and their blends were quantified under increased O2/CO2 atmosphere (21, 30, 40 and 60%) using a thermogravimetric analysis. Observed percentages of CG mass loss and its maximum were higher than those of SS. Under the same atmospheric O2 concentration, both higher ignition and lower burnout temperatures occurred with the increased CG content. Results showed that ignition temperature and comprehensive combustion index for the blend of 60%SS-40%CG increased, whereas burnout temperature and co-combustion time decreased with the increased O2 concentration. Artificial neural network was applied to predict mass loss percent as a function of gas mixing ratio, heating rate, and temperature, with a good agreement between the experimental and ANN-predicted values. Activation energy in response to the increased O2 concentration was found to increase from 218.91 to 347.32 kJ·mol−1 and from 218.34 to 340.08 kJ·mol−1 according to the Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa methods, respectively.

A reactive molecular dynamics study of CH4 combustion in O2/CO2/H2O environments

CH4 oxidation in O2/CO2/H2O environments was studied using reactive molecular dynamics (ReaxFF-MD) method with the aim to investigate the chemical effects of CO2 and H2O under different conditions. The influence of molar heat capacity and thermal radiation of CO2 and H2O were eliminated, which estimated that only chemical effects were taken into account. The results showed that high concentration of CO2 inhibited the reaction rate of CH4 at low temperatures, but advanced CH4 oxidation rate at high temperatures because of CO2 reactivity expressed by CO2+H→CO+OH (R1). The presence of H2O promoted the oxidation rate of CH4 even at low temperatures. Reacting with O and H radicals through H2O+O→OH+OH (R2) and H2O+H→H2+OH (R3) dominate the effect of H2O. Furthermore, the interaction between CO2 reactivity and H2O reactivity was studied in O2/CO2/H2O combustion under fuel rich condition. It was shown that the presence of 30%H2O promoted the conversion rate of CO2 at relatively low temperatures by providing more H radicals for R1, therefore enhanced CO production. However, an inhibition effect of H2O on CO2 conversion rate was found at high temperatures. R3 tended to occur at high temperatures, which would compete with R1 and thus the production of CO was suppressed. The main elementary reactions for CO2 and H2O were studied by analyzing the computed trajectory of the systems during ReaxFF-MD simulations. Finally, the effects of oxygen concentration on CH4/O2/CO2/H2O systems were also studied. The results showed that the effect of CO2 and H2O were less pronounced with increasing O2 concentration.

Enzyme kinetics modelling approach to evaluate the impact of high CO2 and super-atmospheric O2 concentrations on respiration rate of pomegranate arils

ABSTRACTSuper-atmospheric O2 has been shown to affect respiration rate (RR), but no model describing its effect on RR for pomegranate arils has been reported. This study investigated the effects of four different gas compositions (5 kPa O2, 10 kPa CO2 and 85 kPa N2; 10 kPa O2, 5 kPa CO2 and 85 kPa N2; 70 kPa O2, 10 kPa CO2 and 20 kPa N2; and air) on RR of pomegranate arils (cv. Wonderful) stored at 5°C. Michaelis–Menten enzyme kinetics models were used to investigate the effect of CO2 inhibition on O2 consumption rate. Respiratory quotient was used to determine fermentation threshold. The O2 consumption rate increased from 0.87 to 2.81 mL/kg h, with increase in O2 concentration from 5 kPa to 70 kPa. All enzyme kinetics model parameters adequately described the influence of gas concentration on aril RR with correlation coefficient (R2adj = 81–91%).

Experimental study on oxy-fuel combustion of heavy oil

Oxy-fuel combustion of heavy oil can be applied to oil field steam injection boilers, allowing the utilization of both heavy oil and CO2 resources. The present study investigated the oxy-fuel combustion characteristics of heavy oil under different conditions, including the flame, temperature, and pollutant emission characteristics. The results showed that heavy oil combustion was stable at O2 concentrations of 29%, as the O2 concentration was increased, the flame began to brighten gradually, becoming shorter and thicker, while the temperature gradient became higher and the high temperature zone moved closer to the burner exit. The overall temperature and the combustion rates in O2/CO2 atmospheres were below those seen in O2/N2 atmospheres. The volume of NO emitted in the flue gas was almost unaffected by the change in O2 concentrations in atmospheres containing high concentrations of CO2, but it increased rapidly with increasing O2 concentration in O2/N2 atmospheres.

Exergy Destruction Mechanism of Coal Gasification by Combining the Kinetic Method and the Energy Utilization Diagram

Gasification is the core unit of coal-based production systems and is also the site where one of the largest exergy destruction occurs. This paper reveals the exergy destruction mechanism of carbon gasification through a combined analysis of the kinetic method and the energy utilization diagram (EUD). Instead of a lumped exergy destruction using the traditional “black-box” and other models, the role of each reaction in carbon gasification is revealed. The results show that the exergy destruction caused by chemical reactions accounts for 86.3% of the entire carbon gasification process. Furthermore, approximately 90.3% of exergy destruction of chemical reactions is caused by the exothermal carbon partial oxidation reaction (reaction 1), 6.0% is caused by the carbon dioxide gasification reaction (reaction 2), 2.4% is caused by the steam gasification reaction (reaction 3), and 1.3% is caused by other reactions under the base condition. With increasing O2 content α and decreasing steam content β, the proportion of exergy destruction from reaction 1 decreases due to the higher gasification temperature (a higher energy level of energy acceptor in EUD), while the proportions of other reactions increase. This shows that the chemical efficiency is optimal when the extent of reactions 1 and 3 is equal and the shift reaction extent approaches zero at the same time.

Effect of nitrogen addition to ozone generation characteristics by diffuse and filamentary dielectric barrier discharges at atmospheric pressure

Ozone is widely used for gas treatment, advanced oxidation processes, microorganisms inactivation, etc. In this research, we investigated the effect of nitrogen addition to ozone generation characteristics by atmospheric pressure Townsend discharge (APTD) type and filamentary dielectric barrier discharge (DBD) type ozone generators. The result showed that the ozone generated by the filamentary DBD increases rapidly with the increase of O2 content, and is higher than that by the APTD. On the other hand, it is interesting that the ozone generated by the APTD gradually decreases with the increase of O2 content. In order to clarify why the characteristics of ozone generation by the two kinds of discharge modes showed different dependency to the N2 content, we analyzed the exhaust gas composition using FTIR spectroscopy and calculated the rate coefficients using BOLSIG+ code. As a result, we found that although O2 content decreased with increasing N2 content, additional O atoms produced by excited N2 molecules contribute to ozone generation in case of APTD.

Mineral transformation and emission behaviors of Cd, Cr, Ni, Pb and Zn during the co-combustion of dried waste activated sludge and lignite

Co-combustion of dried waste activated sludge (WAS) and lignite was conducted in a horizontal tube furnace system. The mineral transformation and emission behaviors of Cd, Cr, Ni, Pb, and Zn during combustion were examined. The above heavy metals (HMs) were selected because they are more abundant in WAS than in lignite. In the combustion condition of 1000°C–21% O2–30min, the minerals in lignite ash were mainly anorthite (CaAl2Si2O8), quartz (SiO2), pyroxene [Ca(Mg,Fe)Si2O6], and albite (NaAlSi3O8). By contrast, the minerals in WAS ash were mainly quartz (SiO2), anorthite (CaAl2Si2O8), and hematite (Fe2O3). When 90% lignite and 10% WAS were co-combusted, hematite was hardly detected in the combustion product because hematite reacted with quartz and calcium oxide, which are abundant in lignite ash, and generated a large amount of pyroxene. Anorthite and pyroxene were generated continuously during the combustion process, but albite was mainly generated during the first 5min of combustion. High temperature promoted the generation of complex components, such as sodian anorthite [(Ca, Na)(Si, Al)2Si2O8 or (Ca, Na)(Si, Al)4O8]. High O2 concentration promoted the reaction among the three main mineral elements, i.e., silicon, aluminum, and calcium, and generated a large amount of anorthite. During the co-combustion of WAS and lignite, the volatilization percentages of Cd, Pb, and Zn exceeded 30% after a combustion time of 30min, and the order was Cd>Pb>Zn. By contrast, the volatilization percentages of Cr and Ni were lower than 15%. High temperature caused an increase in the volatility of HMs, especially Zn and Ni, although the volatilization percentage of Ni remained low. High O2 concentration also caused an increase in the volatility of HMs, except for Cr and Ni, which showed a slight increase or decrease with increasing O2 concentration in the inlet atmosphere.

Dynamics of Bed for Regeneration of Cerium Oxide High-Temperature Coal Gas Desulfurization Sorbent

The dynamic behavior of bed for regeneration of cerium oxide high temperature gas desulfurization sorbent under the atmosphere of O2 was investigated in the fixed bed micro-reactor. O2 concentration during the regeneration can be detected by an oxygen analyzer, and the sulfur content of sorbent in the bed was test using sulfur analyzer. The effects of O2 concentration, regeneration temperature on the dynamic behavior of bed for regeneration of CeO2 desulfurization sorbent were discussed. According to the experimental results, the length and movement speed of regeneration zone are calculated. The results showed that the increase of O2 concentration in inlet gas obviously improves the movement speed of regeneration zone in bed for CeO2 desulfurization sorbent, and the increase of regeneration temperature can decreased the length of the regeneration zone and improved the movement speed of the regeneration zone. The increase of regeneration temperature had a better effect on the improvement of bed utilization of sorbent than that of O2 concentration.

Oxygen and temperature effects on the electrochemical and electrochromic properties of rf-sputtered V2O5 thin films

Vanadium pentoxide (V2O5) thin films grown by rf-sputtering have been studied as a function of two growth parameters, O2 content and substrate temperature, which influence importantly their structural, as well as their electrochemical and electrochromic properties. The increase in O2 content appears to result in an increase of the grain size of the films, while the increase in substrate temperature leads in platelets perpendicular to the substrate, which enhance the porosity of the films. Films with low O2 content (3%) and films grown at a substrate temperature of 300°C, present enhanced charge storage properties of 553mA h g−1 and large transmittance modulation ability. On the contrary, high O2 content (11%) and a substrate temperature of 150°C lead to improved coloration efficiency (at λ=400nm), reaching values of 84.5 and ∼132cm2C−1, respectively. These findings are discussed in terms of structural and morphological changes occurring during the two parameters studied.

Effect of potassium-doping and oxygen concentration on soot oxidation in O2/CO2 atmosphere: A kinetics study by thermogravimetric analysis

In oxy-fuel combustion, switching from nitrogen to carbon dioxide atmosphere with higher oxygen concentration will affect the oxidation rate of soot, and it was observed in our recent study on soot emission from biomass pyrolysis that potassium (K) crystals are embedded in soot and its precursor clusters. In this study, the effects of K-doping (KCl and K2SO4) and O2 concentration on soot oxidation in O2/CO2 atmosphere are studied using thermogravimetric analysis (TGA), and the extent of catalysis is compared with that in O2/N2 atmosphere. The delays on start, peak and end temperatures of soot oxidation are observed in O2/CO2 atmosphere. However, increase in O2 concentration which promotes oxidation significantly reduces the delay. All the K-doping cases results in accelerated soot oxidation rate, but catalytic role of the K-doping in O2/CO2 is significantly lower than that in O2/N2 because the CO2-enriched environment inhibits the performance of potassium as oxygen carrier. The accelerating degree from K-doping is also affected by the potassium type, doping mass and oxygen concentration. KCl acts as a better, more efficient doping agent than K2SO4 with the increase in doping mass. The catalytic effect of K2SO4 will not change and even decrease at 375μmol(K)/g(soot) for K2SO4 while the catalytic role of KCl keeps increasing even at 600μmol(K)/g(soot) for KCl. In O2 concentration range of 5–30%, the accelerating degree from K-doping presents the minimum value around 15%. This phenomenon strongly approves the hypothesis that potassium as the oxygen carrier and accelerating the oxygen transportation, because in the cases of without K-doping and at a high O2 concentration there is no additional active site for more O2 adsorption thus inducing the slow accelerating degree. The kinetic analysis indicates the first order reaction for soot oxidation and also a good compensation relation between apparent activation energy E and logarithmic frequency factor A. E is generally reduced with the atmosphere changing from O2/N2 to O2/CO2, with K-doping, and with O2 concentration decreasing. This study is beneficial to demonstrate the mechanism of how potassium doping and oxygen concentration affect soot oxidation rate in oxy-fuel combustion environment.

Naphthalene Decomposition by Dielectric Barrier Discharges at Atmospheric Pressure

Naphthalene decomposition in O2/N2 gas mixture with different O2 concentrations has been studied in a dielectric barrier discharge reactor at atmospheric pressure. O2 played an important role in the decomposition of naphthalene, especially in the selectivities of CO and CO2. There was an optimal naphthalene decomposition rate at an O2 concentration of about 3%. The CO x selectivity increased up to 83.3% gradually with the O2 concentration increasing from 1% to 20%. Nanoparticles were found in the gas samples, concentrations of which can be reduced greatly through raising the O2 concentration. The decomposition byproducts of naphthalene were obviously different under different O2 concentrations. Some nitrogenous compounds reduced but some oxygenous compounds increased with increasing O2 concentration. The mechanism of naphthalene decomposition was proposed as that naphthalene was first initiated by dehydrogenation and oxidation, and then followed by deep oxidation to CO and CO2.

Impedancemetric YSZ-based oxygen sensor using BaFeO3 sensing-electrode

This paper deals with an impedancemetric sensor based on an yttria-stabilized zirconia (YSZ) using an oxide sensing-electrode (SE) for measuring O2 concentration. Fourteen oxides were examined as the SE materials for selective detection of O2. Among the sensors examined, the YSZ-based sensor using BaFeO3-SE was found to be insensitive to interfering gases such as NH3, H2, C3H6, C3H8, CH4, NO2, NO or CO, while sensitive to only O2 at 600°C. The impedance value |Z| at 10Hz for the sensor using BaFeO3-SE decreased linearly with increasing O2 concentration on a logarithmic scale in the range of 0.05–21 vol.%. The present sensor exhibited quick and repeatable responses to the change in O2 concentration.

Liposome-Encapsulated Hemoglobin Improves Tumor Oxygenation as Detected by Near-Infrared Spectroscopy in Colon Carcinoma in Mice.

Liposome-encapsulated hemoglobin (LEH) with high (h-LEH, P50 O2 =10mmHg) or low O2 affinity (l-LEH, P50 O2 =40mmHg) may improve O2 delivery to sensitize tumor tissues for radiotherapy. A total of 10mL/kg of h-LEH, l-LEH, red blood cells (RBCs), or saline was infused in mice transplanted with murine colon carcinoma with near-infrared spectroscopy (NIRS) detectors set at the tumor (right leg) and intact muscle (left leg). NIRS recorded changes in the amount of oxyhemoglobin (oxyHb), deoxyhemoglobin (deoxyHb), and their sum (tHb) with the animals spontaneously breathing room air (10min), pure O2 (5min), and then back to room air. The tumor was finally excised for histological examination. In mice treated with h-LEH, tHb significantly increased compared to mice receiving other solutions. The magnitude was significantly attenuated in the tumor compared to the intact muscle under room air. Reciprocal changes in oxyHb and deoxyHb between intact muscle and tumor in response to infused solutions allowed assumption of average tissue PO2 between 30 and 40mmHg in muscle and at around 10mmHg in tumor. While O2 respiration increased oxyHb and decreased deoxyHb both in muscle and tumor, their sum or tHb consistently decreased in muscle and increased in tumor regardless of preceding infusion. Such responses were totally reversed when mice were placed under hypoxia (10% O2 ), suggesting that a lack of physiological circulatory regulation in tumor may account for heavier immunohistochemical staining for human hemoglobin in tumors of mice treated with h-LEH than with l-LEH. The results suggest that h-LEH may cause significant tumor oxygenation compared to RBC, l-LEH, or saline probably due to its nanometer size (vs. RBC) and high O2 affinity (vs. l-LEH) without increasing O2 content in the intact tissue (vs. O2 respiration) probably due to a lack of physiological circulatory regulation.

Cardiopulmonary mortality and COPD attributed to ambient ozone

Tropospheric ozone is the second most important atmospheric pollutant after particulate matter with respect to its impact on human health and is increasing of its concentrations globally. The main objective of this study was to assess of health effects attributable to ground-level ozone (O3) in Kermanshah, Iran using one-hour O3 concentrations measured between March 2014 and March 2015. The AirQ program was applied for estimation of the numbers of cardiovascular mortality (CM), respiratory mortality (RM), and hospital admissions for chronic obstructive pulmonary disease (HA-COPD) using relative risk (RR) and baseline incidence (BI) as defined by the World Health Organization (WHO). The largest percentage of person-days for different O3 concentrations was in the concentration range of 30–39µg/m3. The health modeling results suggested that ~2% (95% CI: 0–2.9%) of cardiovascular mortality, 5.9% (95% CI: 2.3–9.4) of respiratory mortality, and 4.1% (CI: 2.5–6.1%) of the HA-COPD were attributed to O3 concentrations higher than 10µg/m3. For each 10µg/m3 increase in O3 concentration, the risk of cardiovascular mortality, respiratory mortality, and HA-COPD increased by 0.40%, 1.25%, and 0.86%, respectively. Furthermore, 88.8% of health effects occurred on days with O3 level less than 100µg/m3. Thus, action is needed to reduce the emissions of O3 precursors especially transport and energy production in Kermanshah.

Assessment of coal and sawdust co-firing power generation under oxy-combustion conditions with carbon capture and storage

Biomass as a renewable energy source with neutral carbon impact offers a good potential solution for reducing greenhouse gas emissions in conventional coal fired power plants. Therefore, the current paper presents and assesses a conceptual design for large scale sawdust and coal direct co-firing electricity production under oxy-fuel combustion conditions with CO2 capture and storage (CCS) using feedstocks with different coal and sawdust content. The influence of sawdust co-firing on several key technical performance indicators (energy efficiency, auxiliary power consumption, specific CO2 emissions, etc.) was evaluated under the following oxy-fuel atmospheres: 21.8% O2, 28.4% O2 and 35% O2 concentration. The impact of the air separation unit on process performance was tested for oxygen purities of 95% and 99%. It was found that under constant CO2 capture (CC) rate (93%), residual O2 concentration (8%) and gross electrical output (1000 MWe), power plant performances are continuously decreasing with the increase of sawdust feedstock content and supplied oxygen purity. The results also indicate that the increase of O2 concentration in the oxy-fuel atmosphere from 21.8% O2 to 28.4% O2 has a positive impact on process performance while the further increase to 35% O2 leads to lower energy efficiencies.

Greenhouse gas emissions from green waste composting windrow

The process of composting is a source of greenhouse gases (GHG) that contribute to climate change. We monitored three field-scale green waste compost windrows over a one-year period to measure the seasonal variance of the GHG fluxes. The compost pile that experienced the wettest and coolest weather had the highest average CH4 emission of 254±76gCday−1 dry weight (DW) Mg−1 and lowest average N2O emission of 152±21mgNday−1 DW Mg−1compared to the other seasonal piles. The highest N2O emissions (342±41mgNday−1 DW Mg−1) came from the pile that underwent the driest and hottest weather. The compost windrow oxygen (O2) concentration and moisture content were the most consistent factors predicting N2O and CH4 emissions from all seasonal compost piles. Compared to N2O, CH4 was a higher contributor to the overall global warming potential (GWP) expressed as CO2 equivalents (CO2 eq.). Therefore, CH4 mitigation practices, such as increasing O2 concentration in the compost windrows through moisture control, feedstock changes to increase porosity, and windrow turning, may reduce the overall GWP of composting. Based on the results of the present study, statewide total GHG emissions of green waste composting were estimated at 789,000Mg of CO2 eq., representing 2.1% of total annual GHG emissions of the California agricultural sector and 0.18% of the total state emissions.

Poisoning effect of oxygen on hydrogenation performance of a Zr-V-Ni Laves phase alloy

Zr-based Laves phase alloys have been considered as suitable getter materials for hydrogen isotopes recovery, storage and delivery and received considerable attention during past decades. This work focuses on hydrogenation performance of a pseudo-binary Zr-V-Ni Laves phase alloy with the composition of Zr(V0.95Ni0.05)2 after pre-exposure in different contents of O2. It is found that introduced pure oxygen can be rapidly absorbed by the fully activated Zr(V0.95Ni0.05)2 alloy within 40 s. All of the experimental samples pre-exposed in oxygen consist dominant C15 type ZrV2 Laves phase and minor Zr3V3O oxides. With the further increase the oxygen pressure to 4.0 kPa in specimen chamber, Bragg peaks of Zr2V, V-rich BCC solid solution phase and ZrO2 phase, including baddeleyite (α-ZrO2) with monoclinic structure and a small amount of tazheranite (γ-ZrO2) with cubic structure are observed in addition to the dominant ZrV2 and minor Zr3V3O phases. Meanwhile, it can be seen that the lattice parameter of cubic C15 type ZrV2 calculated from Rietveld refinement increases from 7.402 to 7.432 Å with the increase of O2 content and the corresponding unit cell volume increases 0.86 vol.% as the O2 pressure from 1.0 to 4.0 kPa, which indicates more oxygen atoms have been dissolved into the lattice of ZrV2. All of the oxygen poisoned Zr(V0.95Ni0.05)2 alloys can absorb hydrogen and the capacity decreases from 3.39 to 2.22 H A−1 with the increase of oxygen pressure from 1.0 to 4.0 kPa, comparing with the maximum hydrogen storage capacity (4.34 H A−1) of the fully activated fresh alloy. The existence of oxygen is found to decrease both capacity and kinetics of Zr(V0.95Ni0.05)2 by forming passivation layer oxides which block the dissociation of H2 molecule on the surface.