CO Molar Ratio Research Articles

Pyrolysis-catalytic steam/dry reforming of processed municipal solid waste for control of syngas H2:CO ratio

The production of syngas from the pyrolysis-catalytic reforming of processed municipal solid waste in the form of refuse derived fuel has been investigated experimentally using a two-stage fixed bed reactor with a 10 wt% Ni–Al2O3 catalyst. The reforming gases used were a combination of steam and carbon dioxide (dry reforming). The main focus of the research was to manipulate the H2:CO ratio in the syngas for targeted end-use applications by optimizing the process conditions, including the input steam/CO2 reforming gas ratio. The experimental results showed that at higher steam:CO2 ratios, there was a marked increase in H2 yield due to the endothermic nature of the steam and CO2 reforming processes. The catalytic reforming temperature also had a major influence on H2 yield, with increasing temperature raising the hydrogen yield to a maximum of ∼41.0 mmol gRDF−1 at 955 °C catalyst temperature. The H2:CO molar ratio was also affected by the process variables and were interdependent on them. For example, the influence of an increase in the catalytic reforming temperature as the content of steam in the reforming gas input was also increased, produced a maximum H2:CO molar ratio of ∼4.7:1 achieved at an input steam:CO2 ratio of 75:25 and a catalyst temperature of 700 °C. Whereas, at higher CO2 content in the reforming gas, the product H2:CO ratio was ∼1:1. Also, for a steam:CO2 input ratio of 50:50, the H2:CO ratio produced was ∼2:1 and for higher steam content in the reforming gas the product H2:CO was ∼3:1. Design of Experiments (DoE) modelling was carried out using the experimental data to identify the process conditions that would produce a target syngas H2:CO molar ratio of 1:1 and 2:1. The predicted optimised process conditions from the DoE modelling produced experimental results close to the targeted syngas H2:CO molar ratios, thereby validating the DoE model.

Synergy between Cobalt–Chromium-Layered Double Hydroxide Nanosheets and Oxidized Carbon Nanotubes for Electrocatalytic Oxygen Evolution

Enormous potential loss and sluggish kinetics of the oxygen evolution reaction (OER) limit the practical implementation of water electrolyser systems. We attempt to address these technical challenges through the synthesis of cobalt–chromium-layered double hydroxide nanosheets (CoCr LDH) on oxidized-carbon nanotube (O-CNT) backbones as efficient OER electrocatalysts. Microscopic and elemental distribution analysis suggests that interconnected sheets of CoCr LDH masks over O-CNTs. We tested various compositions of the CoCr LDH_O-CNT hybrid (by varying the molar ratios of Co and Cr) along with the weight adjustment between CoCr LDH and O-CNTs to obtain an optimal OER activity. Due to the synergistic effect, the CoCr-LDH(3:1)_O-CNT (2:1) exhibits the lowest overpotential of 290 mV at 10 mA cm–2 with a corresponding smaller Tafel slope of 42 mV dec–1, which outperforms the other tested materials. The catalytically active site of Co2+ is boosted by Cr3+ as a charge transfer site owing to the spin–spin coupling between 3d7 of Co and 3d3 of Cr3+, which is evidenced by electron paramagnetic resonance results. Furthermore, the mildly oxidized carbon nanotubes offer the conducting channels to CoCr-LDH for faster charge transfer during OER.

Selective Photocatalytic Reduction of CO2 to Syngas Over Tunable Metal-Perovskite Interface.

The extensive emission of CO2 results in critical environmental issues, such as global warming. Photocatalytic CO2 conversion is a meaningful route to convert CO2 into useful chemicals. However, the highly selective reduction of CO2 with the avoidance of hydrogen evolution is still challenging. Herein, the photocatalytic reduction CO2 to synthesis gas (syngas) was achieved on a metal Ag socketed perovskite LaFeO3 (LFO) catalytic interface prepared by an in-situ exsolution method. The conduction band of Ag-exsolved LFO is more negative than LFO, benefiting efficient CO2 reduction. By tuning the dopant Ag cation in the lattice to nanoparticles pinned on the surface, the CO formation rate was improved around five-fold from 0.51 to 2.41 μmol g-1 h-1 . Meanwhile, the H2 /CO molar ratio also showed strong dependence on the modality of Ag at the metal-perovskite interface. The design offers a promising pathway for transforming CO2 to valuable chemicals based on efficient photocatalysts design.

Au/MoS2 tips as auxiliary rate aligners for the photocatalytic generation of syngas with a tunable composition

Synthesis gas (syngas), with a wide range of molar ratios of CO and H2 from 0.3 to 4, can serve as an important feedstock in the petroleum industry for the production of various synfuels; however, it remains a major challenge to tune the composition over such a wide range of ratios. Here, we demonstrate the photocatalytic production of syngas with tunable H2/CO molar ratios via rationally designed Au/MoS2 symmetrically tipped CdS nanowires (AMTCs), in which MoS2 and Au serve as cocatalysts for the hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR), respectively. The competing reactions are controlled and aligned through the selective decoration of size-controlled (1–50 nm) Au nanoparticles on MoS2 by controlling the charge transfer kinetics during photodeposition. Finally, the widest range of H2/CO ratios in syngas reported to date, ranging from 0.35 to 3.6, is realized, indicating that this is a potentially efficient approach for solar-to-syngas production by using rationally designed nanostructures.

Controllable Synthesis of a Loofah-Like Cobalt-Nickel Selenide Network as an Efficient Electrocatalyst for the Hydrogen Evolution Reaction.

The rational design and construction of noble metal-free electrocatalysts featuring high efficiency and low cost are important for the hydrogen evolution reaction (HER). A significant development in the synthesis of a loofah-like Co0.6Ni0.4Se2 architecture (expressed as Co0.6Ni0.4Se2-LN) electrocatalyst on carbon cloth through a three-step method is reported. Both the ionic liquid 1-dodecyl-3-methylimidazolium acetate (IL, [C12MIm]Ac) and the molar ratio of Co to Ni play a pivotal role in the synthesis of Co0.6Ni0.4Se2-LN with 3D hierarchical architecture. Co0.6Ni0.4Se2-LN exposes abundant active sites and provides hierarchical and stable transfer channels for both electrolyte ions and electrons, which results in outstanding HER performance. Impressively, Co0.6Ni0.4Se2-LN shows a low overpotential of 163 mV at 10 mA cm-2, a small Tafel slope of 40 mV dec-1, and superior stability to continuously catalyze the generation of H2 for 40 h. This study offers a new perspective to the synthesis of high-efficiency inexpensive electrocatalysts for HER and also presents a good example for investigating the potential application of ILs in the synthesis of functional materials.

Hydroxyl radical induced from hydrogen peroxide by cobalt manganese oxides for ciprofloxacin degradation

Advanced oxidation processes (AOPs) are promising technology to remove organic pollutant in water. However, the main problem in the AOPs is the low generation of hydroxyl radical (•OH) owing to the low decomposition efficiency of hydrogen peroxide (H2O2). Herein, the spinel type cobalt acid manganese (MnCo2O4) with flower morphology was fabricated through a co-precipitation method. In situ Fourier transform infrared spectroscopy confirms that the MnCo2O4 with the optimal molar ratio of Co and Mn precursors (CM3, Co:Mn = 3) has more Lewis acid sites compared with single metal oxide catalysts (Co3O4 and Mn2O3), leading to the excellent performances for H2O2 decomposition rate constant on CM3, which is about 15.03 and 4.21 times higher than those of Co3O4 and Mn2O3, respectively. As a result, the obtained CM3 shows a higher ciprofloxacin degradation ratio than that of Co3O4 and Mn2O3. Furthermore, CM3 shows an excellent stability during several cycles. This work proposes effective catalysts for ciprofloxacin decomposition and provides feasible route for treating practical environmental problems.

Ammonium nickel‐cobalt phosphate nanoflowers on highly conductive carbon fibers as an electrode material for enhanced electrochemical performance supercapacitors

AbstractThe nickel cobalt ammonium phosphate (NH4(Ni, Co)PO4)/carbon fibers (CFs) electrode materials were prepared by a hydrothermal method. The nanoflower‐like active materials (NH4(Ni, Co)PO4) have an average particle size of about 500 nm, which are uniformly and tightly dispersed on the surface of CFs. The specific capacitance of the composite electrode NCCF‐3 with a molar ratio of Co and Ni of 1:1 is as high as 811.1 F·g−1 at the current density of 1.25 A·g−1. Meanwhile, the electrochemical performance of NCCF‐3 exhibits a good reversibility and batter stability of 89.1% capacitance retention after 2000 cycles. The maximum energy density of NCCF‐3 is 20.28 Wh·kg−1 at the power density of 189.17 W·kg−1. The electric double‐layer of the high‐conductivity CFs combined with the pseudocapacitance of NH4(Ni, Co)PO4 will help to improve their electrochemical performances. The NCCF‐3 electrode materials, which can effectively improve the capacitance and stability, are a potential composite electrode for the applications of a supercapacitor.

Synthesis of Ni(Co)MoO4 with a mixed structure on nickel foam for stable asymmetric supercapacitors

In this work, the Ni(Co)MoO4 (NMO-Co) hybrid materials with nanoneedle and nanosheet structure were prepared on nickel foam (NF) by the hydrothermal method for high-stability supercapacitors. The effect of Co presence on the structure and electrochemical properties of NMO-Co was investigated. As the molar of Cobalt increased, more nanoneedles grew on the surface of NiMoO4/NF. The combination of the Ni-doped CoMoO4 nanoneedles and Co-doped NiMoO4 nanosheets was irregularly arranged on the surface of NF, which emerged an improvement of the cycling performance. When the molar ratio of Co: Ni: Mo was 0.5: 1: 1, the capacitance retention of the hybrid electrode was 80.1% after 10,000 cycles at 10 A g−1, while the pure NiMoO4 electrode was 53.1%. Moreover, an asymmetric supercapacitor device displayed high energy density and power density. The maximum energy density and power density could reach 55.71 Wh kg−1 and 14,999 W kg−1, respectively. The hybrid electrode's good electrochemical performance is due to the combination of mutual doping of Ni and Co with a mixed morphology.

A comparative study on the turbulent explosion characteristics of syngas between CO-enriched and H2-enriched

Syngas, containing mostly CO and H2, has variant explosion properties for the specific contents. For a further understanding, a comparative study on the turbulent explosion characteristics of syngas between CO-enriched (the mole ratio of CO was 70%) and H2-enriched (the mole ratio of H2 was 70%) were conducted at different equivalence ratios (φ, from 0.4 to 3.0) and turbulent intensities (u'rms, from 0 to 1.309 m/s). The peak value of maximum explosion pressure (pmax) was attained in the stoichiometric explosion of H2-enriched syngas but in fuel-rich explosion of the CO-enriched, the growth extents of pmax seemed more sensitive to u'rms for H2-enriched syngas compared to CO-enriched syngas. The lowest values of explosion duration (tc) was attained in fuel-rich explosions for both CO-enriched and H2-enriched syngas but different corresponding φ to the lowest tc, the phenomena were analyzed from the aspects of ignition delay time, laminar burning velocity, intrinsic instabilities, and flame/turbulence interaction. Finally, the pressure rising was comparatively observed, the maximum pressure rise rate ((dp/dt)max) expressed more similar variation regulations to tc rather than pmax, which meant flame propagation speed plays a more important role on the evolution of pressure rising.

Miscibility characteristics of the CO2/n-hexadecane system with presence of water component based on the phase equilibrium calculation on the interface region

In correspondence to the bright prospects of CO2 EOR technology on greenhouse gas geological storage as well as oil recovery enhancement practices, the phase equilibrium characteristics of CO2/oil/water system was investigated in this paper. n-Hexadecane (n-C16H34) is employed as the oil component and water is introduced into the two phase system as the dissolved component in CO2. PR-EOS with modified alpha functions and Binary Interaction Parameters (BIPs) is employed to calculate the Minimum Miscibility Pressure (MMPs) of the CO2/n-C16H34 system with or without water presence at three temperatures of 40.3 ℃, 55.4 ℃ and 70 ℃. Calculation model and the employed parameters were validated through comparison with corresponding measurements, including the observation on decreased MMPs of the CO2/H2O/n-C16H34 system in comparison with the CO2/n-C16H34 system. Parameter studies were carried out for the CO2/n-C16H34 system with or without water presence at different molar ratios. It is found the existence of water component could reduce the MMP values of the CO2/n-C16H34 system and the degree of the MMP reduction was related to the molar ratio of CO2 in the system. Higher CO2 molar ratio could result in larger MMP deviation between CO2/C16H34 system and CO2/H2O/C16H34 system.

Effects of ammonium chloride on structural stability of cobalt carbonate hydroxide and their improved electrochemical performance for supercapacitor

Transition metal salts are potential materials for energy storage and conversion. However, their application is limited by poor morphology retention and performance stability during charge/discharge processes. Herein, the interlaced rod-like Co(CO3)0.5(OH)·0·11H2O (CCO) are prepared on nickel foam (NF) by hydrothermal method. During the experiment, the reaction solution is changed from weak basic to weak acidity with the increase of NH4Cl, and it has obvious influence on the growth and electrochemical performance of the as-prepared CCO. When the molar ratio of CO(NH2)2/NH4Cl in solution is 1:2.8 (the pH value of solution is 5.42), the microstructure of CCO nanorods (NRs) are obviously different from that obtained by other molar ratios, and many nanofloccules surrounded on their surface. Moreover, they show improved electrochemical performance, and the specific capacities are 2115.1 and 1400 C/g at 1 and 20 A/g, respectively. Especially, the structure of CCO NRs is remained after 3000 electrochemical cycles, and the specific capacity only lost 3% of the initial value, showing their good cycle stability. In addition, an assembled hybrid CCO NRs/NF//AC device can output a specific energy of 41.8 Wh/kg at 850.7 W/kg. These results can fully prove that the as-prepared CCO NRs is a good candidate for high-performance electrode material.

Catalytic toluene steam reforming using Ni supported catalyst from pyrolytic peat

The paper aims to investigate an effective method of catalytic reforming of toluene using peat char-supported Ni metal to achieve clean gas production. Utilizing KOH or CO2 activation to increases the surface area and pore volume of peat char during catalyst preparation. The chemical and structural properties of catalysts is explained based on SEM, EDS, XRD, BET method. Meanwhile, the influence of reaction temperature, residence times (τ), steam-to‑carbon ratios (S/C) in catalytic reaction and the molar ratio of CO, CO2, H2, CH4 in clean gas were investigated. The results indicated that SiO2 structure plays a significant role in nickel-based peat char catalyst, and the catalyst exhibited high catalytic performance. Conversion efficiencies of toluene can reach about 95.3% using Ni/APC catalyst at residence time of 0.5 s, steam-to‑carbon ratio of 3:1, temperature of 850 °C. The catalyst also exerted a positive effect on the syngas (CO + H2) production with the maximum molar ratio reaching up to 94.7 mol% under the optimized conditions. The high catalytic activity was mainly attributed to the structure of AlNi2Si and NiSi on the catalyst surface. Therefore, the cost-effective peat char-supported Ni catalysts could be used for aromatic tar conversion.

Highly efficient removal of quinolones by using the easily reusable MOF derived-carbon

As anthropogenic antibiotics, quinolones, e.g., ofloxacin have adverse impacts on ecological systems and human heaths. The removal of quinolones is of great importance, and adsorption techniques have been widely used to remove this hazardous contaminant. However, a robust and easy-operating adsorbent is still emergently required due to the complex chemical structure of quinolones. In this study, we successfully synthesized the promising metallic carbons (MCs) containing carbon nanotubes and cobalt nanoparticles by carbonizing Zn/Co-ZIF at 900 °C. Three different molar ratios of Co and Zn were applied to optimize the adsorption capacity on ofloxacin (OFL). Results showed MC with molar ratio of Co and Zn at 3:1 (Co-CNT/NPC3/1) achieved the maximal adsorption capacity to 118.3 mg g-1. Its adsorption performance was satisfied in the pH range from 5 to 9 and ionic strengths at 0.01 M. The main mechanisms for these adsorptions were identified as electrostatic attraction, metal coordination and π-π EDA. Removal efficiencies of quinolones higher than 68 mg g-1 indicated the strong feasibility of this adsorbent for wastewater treatments. The regeneration of Co-CNT/NPC3/1 at 600 °C allowed its at least 4-time reusability and its magnetic property enabled external magnets to recycle it from real environments.

Bimetallic oxides with package structure for enhanced degradation of bisphenol a through peroxymonosulfate activation

Cobalt oxide (CoO) could activate peroxymonosulfate (PMS) to remove pollutants but the catalytic performance was restricted by limited active sites and it was with risk of harmful cobalt ion leaching. In order to solve these problems, bimetallic oxides with package structure were researched by dispersing CoO nanoparticles on a stable support (magnesium oxide, MgO) via simple one-step coprecipitation method. Co-Mg bimetallic oxides with minute quantities of CoO and highly dispersed structure could efficiently activate PMS for degradation of bisphenol A (BPA). The catalytic properties of catalysts with different molar ratios of Co and Mg were evaluated. The optimal molar ratio (0.075:15) of Co and Mg was found in the Co-Mg bimetallic oxides, which could maximize its catalytic performance for PMS in a wide pH range. Influences of different systems, catalyst dosages, PMS concentrations, temperatures, initial pH values and mineralization rates were researched for BPA degradation. And the oxidation capacities to remove BPA in the different aqueous matrices were evaluated for the catalyst/PMS system. The addition of anions and nature organic matter (NOM) showed that there existed positive (Cl- and H2PO4-) and negative (NO3-, HCO3-, HPO42- and NOM) effects for BPA degradation. Additionally, main reactive radicals were certified by quenching experiments. Four successive experiments and evaluation of concentration of cobalt ion leaching illustrated good stability of the catalyst, which was related with its package structure. Finally, activation mechanism of PMS, proposed degradation pathways of BPA and acute toxicity of degradation intermediates of BPA were analyzed.

Highly efficient degradation of sulfamethoxazole (SMX) by activating peroxymonosulfate (PMS) with CoFe2O4 in a wide pH range

The cobalt ferrite materials (CoxFe3−xO4) with different molar ratios of Co:Fe (1:16, 1:8, 1:4, 1:2, and 3:4) were synthesized by simple co-precipitation method, and used for catalyzing activation of peroxymonosulfate (PMS) to degrade sulfamethoxazole (SMX). The effects of catalyst dose, PMS dose, pH value, and inorganic ions on the degradation of SMX were investigated. Particularly, the degradation efficiency of SMX reached 91% within 10 min in CoFe2O4/PMS, and the removal rate of SMX achieved 81% at first 1 min. Meanwhile, the CoFe2O4/PMS reaction system exhibited excellent catalytic performance at a wide pH range from 3.00 to 11.00. The CoFe2O4 catalyst could be easily magnetically separated and exhibited high stability in cycle experiments. EPR and quenching experiments showed that 1O2, SO4−, and OH species were produced in the CoFe2O4/PMS system, especially OH and 1O2 played dominant roles during the degradation of SMX. The catalytic degradation mechanism of SMX in the CoFe2O4/SMX system was proposed, involving radical process and non-radical process. This work will provide a new way for the efficient treatment of wastewater especially those containing SMX compounds.

Influence of Ce2O3 addition on the basicity of Ni/MgO and on its catalytic performance in dry reforming of methane (Turning CO2 to fuel)

The only way to stabilize the Earth’s climate is to stabilize the concentration of greenhousegases in the atmosphere. In this study, the conversion of methane and CO2 to synthesis gasusing dry reforming over catalysts Ni/Mg1-XCeXO (x= 0, 0.03, 0.07, 0.15; 1 wt% Ni each),dry reforming of methane was performed. The catalysts were prepared by K2CO3 coprecipitationfrom aqueous cerium nitrate hexahydrate and magnesium nitrate hexahydrate.Impregnation of nickel (II) acetylacetonate onto MgO-Ce2O3 was then conducted. TEM,XRD, FTIR, XRF, XPS, and BET characterizations of the catalysts were carried out.Results showed that the catalysts were reduced at 700 °C by H2 prior to each reaction. CH4and CO2 conversions at 900 °C of the catalysts after being tested for 200h decreased in theorder Ni/Mg0.85Ce0.15O, Ni/Mg0.93Ce0.07O, Ni/Mg0.97Ce0.03O, and Ni/MgO. The highest H2and CO selectivities, was observed at a 1:1 CH4:CO2 mole ratio. We further performed adry reforming in the presence of low-concentration oxygen flow (1.25 Vol %) and found anincreased CH4 conversion.

CO2 valorization into synthetic natural gas (SNG) using a Co–Ni bimetallic Y2O3 based catalysts

Abstract Recently, because of the increasing demand for natural gas and the reduction of greenhouse gases, interests have focused on producing synthetic natural gas (SNG), which is suggested as an important future energy carrier. Hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. Nickel supported on yttrium oxide and promoted with cobalt were prepared by the wet-impregnation method respectively and characterized using SBET, XRD, FTIR, XPS, TPR, and HRTEM/EDX. CO2 hydrogenation over the Ni/Y2O3 catalyst was examined and compared with Co–Ni/Y2O3 catalysts, Co% = 10 and 15 wt/wt. The catalytic test was conducted with the use of a fixed-bed reactor under atmospheric pressure. The catalytic performance temperature was 350 °C with a supply of H2:CO2 molar ratio of 4 and a total flow rate of 200 mL/min. The CH4 yield was reached 67%, and CO2 conversion extended 48.5% with CO traces over 10Co–Ni/Y2O3 catalyst. This encourages the direct methanation reaction mechanism. However, the reaction mechanism over Ni/Y2O3 catalyst shows different behaviors rather than that over bi-metal catalysts, whereas the steam reforming of methane reaction was arisen associated with methane consumption besides increase in H2 and CO formation; at the same temperature reaction.

Effect of Ni/Co vermiculite as catalysts for Catalytic pyrolysis of plastic wastes

In this study, the modified vermiculite adjusted with Ni and Co for pyrolysis of plastic is characterized by X-ray diffraction (XRD) and Brunauer Emmett Teller (BET). These results indicate that the ratio of Ni and Co can affect the surface area and pore diameter of catalyst. In addition, the results of GC show that Ni and Co not only have a good selectivity of C3, the main gaseous hydrocarbons of pyrolysis products, but also play an important role in dealing with low quality of oil products of plastic pyrolysis by controlling the concentration of metal oxide particles in the vermiculite layer. The adjustment of the molar ratio of Co and Ni can optimize the hydrogenation/dehydrogenation of metal active sites. It means that the greatly catalytic activity of supported Ni and Co catalysts is caused by moderate total acidity, relatively high surface area, and uniformly dispersed oxide particles on vermiculite support. Therefore, it suggests that adopting the clay catalyst is an efficient and environmentally friendly way to produce valuable products in pyrolysis of plastic waste.

Simulation of CO2 photoreduction in a twin reactor by multiphysics models

The production of solar fuels through CO2 photoreduction is a promising process to control CO2 emissions and provide alternative renewable fuels. Recently, a twin photoreactor design has been used to enhance CO2 conversion efficiency. However, the reaction mechanisms and operating conditions are not well understood. Therefore, the purpose of this work is to understand the CO2 photoreduction mechanisms in the twin photoreactor by using multiphysics modelling (COMSOL 5.2a). A 2D axisymmetric model was built and the predicted yield of CH3OH matched the experimental values very well under different molar ratios of CO to CO2. Moreover, the effects of operating parameters, including bubble size, gas volume rate, bubble entrance size and photocatalyst loading, were investigated. The CO2 photoreduction in the liquid phase was shown to be a mass-transfer controlled process, and the flow properties significantly influenced the CO2 photoreduction. It was found that the bubbly circulation flow structure, interfacial area between gas and liquid, and surface area of the catalyst are critical for the CH3OH yield. This study can provide the theoretical guidance for process optimization and reactor design.

Synthesis, thermal stability, magnetic properties, and microwave absorption applications of CoNi-C core-shell nanoparticles with tunable Co/Ni molar ratio

Magnetic alloy-C core-shell nanoparticles with tunable elemental components are highly expected for their controllable magnetic, catalytic, and electromagnetic properties, and high air stability. Here we present a simple one-step metal organic chemical vapor deposition for the synthesis of CoNi-C core-shell nanoparticles with tunable Co/Ni molar ratio. The as-synthesized nanoparticles have core sizes of 5–50 nm, shell thicknesses of ~5 nm, and tunable Co/Ni molar ratio determined by the molar ratio of Co(acac)3/Ni(acac)2 used in the precursor. The core-shell nanoparticles are very stable in ambient atmosphere at the temperature below 200 °C, and exhibit a slight oxidation in the temperature range of 200–400 °C. The core-shell nanoparticles with Co/Ni molar ratios of 1.27:1, 0.64:1, and 0.30:1 exhibit saturation magnetization values of 41, 31, and 24 emu/g, and coercivity values of 483, 346, and 362 Oe, respectively. It is demonstrated that the microwave absorption parameters of the as-synthesized nanoparticles can be tuned by the Co/Ni molar ratio, which provides a practical strategy to regulate the microwave absorption properties of nanostructured absorbers.