Formation Of Impurities Research Articles

Synthesis and Structural Characterization of Process Related Impurities of Mirabegron: A Beta-3 Adrenergic Agonist Drug

In the synthesis of active pharmaceutical ingredient and the development of pharmaceutical products, the impurities profiling plays a significant role. The control of impurities is essential for producing the quality, safe and efficient drug products for therapeutic use. Few works reported for the synthesis of potential impurities and further characterized to support the synthesis route and purity of the synthesized compound. Hence in present study, five impurities of mirabegron such as impurity 3, 4, 6, 8 and 9 were synthesized and structural characterization was carried using NMR, IR and mass spectral studies. Based on the results, it was confirmed that the route of synthesis established in the study was simple, convenient and economical and can be useful for the products of potential impurities of mirabegron. By characterizing each of these impurities, the regulatory need has been met. Additionally, the analytical method development and validation studies have utilized the generated impurity standards. This effort helped with the process development’s optimization stage and made it possible to identify the crucial parts of the process. The production method for mirabegron was carefully adjusted to eliminate or reduce the formation of impurities, which is helpful for the creation of safe pharmaceutical goods.

Mitsubishi Chemical licenses patent for biomass-based polyester to Mitsui Chemicals

Levothyroxine as active pharmaceutical ingredient of formulations used for the treatment of hypothyroidism is distributed worldwide and taken by millions of people. An important issue in terms of compound stability is its capability to react with ambient oxygen, especially in case of long term compound storage at elevated temperature. In this study we demonstrate that ultrahigh-performance liquid chromatography coupled to UV spectrometry and high-resolution mass spectrometry (UHPLC-UV-HRMS) represent very useful approaches to investigate the influence of ambient oxygen on the degradation kinetics of levothyroxine in the solid state at enhanced degradation conditions. Moreover, the impurity pattern of oxidative degradation of levothyroxine is elucidated and classified with respect to degradation kinetics at different oxygen levels. Kinetic analysis of thyroxine bulk material at 100 °C reveals bi-phasic degradation kinetics with a distinct change in degradation phases dependent on the availability of oxygen. The results clearly show that contact of the bulk material to ambient oxygen is a key factor for fast compound degradation. Furthermore, the combination of time-resolved HRMS data and automated data processing is shown to allow insights into the kinetics and mechanism of impurity formation on individual compound basis. By comparing degradation profiles, four main classes of profiles linked to reaction pathways of thyroxine degradation were identifiable. Finally, we show the capability of automated data processing for the matching of different stressing conditions, in order to extract information about mechanistic similarities. As a result, degradation kinetics is influenced by factors like availability of oxygen, stressing time, or stressing temperature, while the degradation mechanisms appear to be conserved.

НОВЫЙ СПОСОБ ПОВЫШЕНИЯ СТЕХИОМЕТРИИ И СТРУКТУРНОГО СОВЕРШЕНСТВА НЕЛИНЕЙНО-ОПТИЧЕСКОГО КРИСТАЛЛА НИОБАТА ЛИТИЯ

Experimental and theoretical data on the influence of В2О3 flux on the crystal-melt system, the structural features, and the optical properties of a crystal of lithium niobate are summarized. The Gibbs energies of the borate impurities formation (Al4B2O9, CaB2O4, CaB4O7, Ca2B2O5, Ca3B2O6, PbB2O4) in a congruent composition charge of lithium niobate are calculated. It was found that the element boron, as an active complexing agent, in the composition of the В2О3 flux aligns the distribution coefficients of lithium (KLi) and niobium (KNb). Also, the element boron is able to prevent the transition of trace amounts of impurity metals into the structure of a lithium niobate crystal. Boron increases the ordering of structural units of the cation sublattice and distorts the anionic framework of the crystal. This is due to the fact that boron is embedded in the tetrahedral voids faces of the crystal structure in trace amounts (4∙10-4 mol.%). This leads to changes in bond lengths O-O of the oxygen octahedra O6, thereby changing polarizability oxygen-octahedral cluster NbO6, determining nonlinear optical and ferroelectric properties of the crystal.

Unexpected transformation of n.c.a. [111In]InCl3 in stock solutions into an unreactive [111In]In-species

While performing multiple indium-111 labeling of DOTA-modified peptides from a single batch of [111In]InCl3, inconsistent radiochemical yields were observed. We found that the formation of a radioactive impurity in the [111In]InCl3 stock solution hampered the reactivity of the indium-111 during radiolabeling reactions. The formation of this unknown 111In-species could be successfully suppressed by increasing the concentration of chloride ions in the stock solution and [111In]InCl3 was “recovered”. Radiolabeling of DOTA-peptides with the stabilized [111In]InCl3 resulted again in acceptable radiochemical yields. In addition, we report convenient iTLC systems that allow distinguishing between [111In]InCl3, the formed unknown 111In-species, radiocolloids, and radiolabeled peptides (DOTANOC).

TRIBOLOGICAL ASPECT OF ASSESSMENT OF EFFICIENCY OF FILTRATION USING MULTI-LAYER MATERIALS

This study presents the results of testing for the efficiency and effectiveness of filtration using multi-layer filter materials, and briefly presents a new technology for manufacturing filter media using these materials. The first part of the article describes the causes of the formation of impurities in operating fluids and the tribological effects of their impact. The second part is dedicated to testing for filtration efficiency and effectiveness for different filter materials. The third part of the article briefly describes the technology for manufacturing filter media using efficient but difficult-to-form materials. The testing results showed significant differences in filtering efficiency and effectiveness between the cellulose samples and the samples of filter materials based on glass microfibre layers. All of the tested multi-layer materials allow filtration effectiveness of over 90% to be achieved over the entire range of impurity sizes included in the experiment. The results of a comparative test for pressure change during filtration also indicate that glass microfibre materials have a considerably longer operating life than cellulose materials. The time after which a sharp increase in pressure occurs (due to the filter layer being filled with impurities) is nearly four times longer for multi-layer materials than for cellulose materials. The methods for cutting, forming, and joining filter materials have been developed by the author of this article and implemented at the EXMOT company.

Investigation of the Process of Simple Distillation in Irrigated Pipe Elements

In modern chemical and oil refining complexes, separation processes are among the most popular and energy-intensive. Installations for their implementation should be equipped with nodes for creating vapor (evaporators) and liquid (deflegmators) irrigation. Evaporators of any type (film, thermosiphon, gas lift, cubic) belong to this class of devices. For example, in cubic evaporators, the gas flow is completely formed from flux bubbles that originate on the heat-conducting surface and float in the volume of the cubic liquid located in the apparatus. Due to the accompanying mass exchange, the bubbles are enriched with volatile components during ascent and noticeably increase in volume, and the growth of the bubble is determined, among other things, by the total flow. At the same time, in real bubbling-type equipment, the total mass transfer surface exceeds the cross-section of the device itself by more than two orders of magnitude. Thus, according to, the ratio of the internal cross-sectional area of the apparatus to the developed mass transfer surface is 0.0015–0.002. Based on the analysis of the integral equation of the diffusion boundary layer, it is shown that the presence of a resultant flow of substance through the phase interface (non-equimolarity of the process) in a two-phase gas (vapor)–liquid system leads to the transformation of the structure of the traditional mass transfer equation itself. The use of a new structure obtained for both binary and multicomponent mixtures makes it possible to significantly simplify the approach to the description and generalization of arbitrary mass transfer processes. The innovativeness of the proposed approach lies in its universality for non-equimolar processes. This simplifies the creation of models of any mass transfer devices and entire production lines. In addition, the proposed approach is a good auxiliary tool for various researchers and experimenters. It should also be noted that the separation processes of many products of organic origin during heating are characterized by the appearance of undesirable side reactions (thermal decomposition, condensation, polycondensation, formation of harmful impurities, etc.), which occur most intensively in the heating zones. At the same time, the evaporation and distillation units are subject to requirements for the minimum hydraulic resistance of the structure, the maximum separation capacity (efficiency), and the minimum residence time of the product in the apparatus (equivalent to the minimum holding capacity of the structure). It was noted that the specified requirements are most fully met by film-type devices.

High ionic conductivity and stable phase Na11.5Sn2Sb0.5Ti0.5S12 for all-solid-state sodium batteries

The quaternary antimony (Sb)-based sulfide sodium solid electrolyte Na11Sn2SbS12 with good moisture stability is attractive for practical application in all-solid-state sodium batteries. However, the Na11Sn2SbS12 exhibits low room temperature ionic conductivity and it is difficult to obtain pure phase due to the limited solubility of Sb in the Na11Sn2SbS12 crystal structure. Herein, titanium (Ti)-doping Na11+xSn2Sb1-xTixS12 (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8, 1.0) materials are systematically investigated, and the highest room temperature ionic conductivity of 1.01 mS cm−1 is achieved when x = 0.5 (Na11.5Sn2Sb0.5Ti0.5S12), which is 3 times higher than that of pristine Na11Sn2SbS12. X-ray diffraction and alternating current impedance analyses reveal that the substitution of Sb with Ti can prevent the formation of the NaSbS2 impurity, determining high ionic conductivity. Meanwhile, the Na11.5Sn2Sb0.5Ti0.5S12 demonstrates good air stability with limited H2S gas evolution. Besides, the activation energy, electronic conductivity and electrochemistry stability window for Na11.5Sn2Sb0.5Ti0.5S12 are also evaluated. Moreover, a high reversible capacity and stable cyclic performance of TiS2 based all-solid-state sodium battery using Na11.5Sn2Sb0.5Ti0.5S12 are demonstrated, showing an initial discharge capacity of 177.6 mAh g−1 at 0.1C with a capacity retention of 83.5% based on the second discharge capacity after 50 cycles at 25 °C.

Binary Cu2-xS Templates Direct the Formation of Quaternary Cu2ZnSnS4 (Kesterite, Wurtzite) Nanocrystals.

Kesterite Cu2ZnSnS4 (k-CZTS) nanocrystals have received attention for their tunable optoelectronic properties, as well as the earth abundance of their constituent atoms. However, the phase-pure synthesis of these quaternary NCs is challenging due to their polymorphism, as well as the undesired formation of related binary and ternary impurities. A general synthetic route to tackle this complexity is to pass through intermediate template nanocrystals that direct subsequent cation exchange toward the desired quaternary crystalline phase, particularly those that are thermodynamically disfavored or otherwise synthetically challenging. Here, working within this model multinary system, we achieve control over the formation of three binary copper sulfide polymorphs, cubic digenite (Cu1.8S), hexagonal covellite (CuS), and monoclinic djurleite (Cu1.94S). Controlled experiments with Cu0 seeds show that selected binary phases can be favored by the identity and stoichiometry of the sulfur precursor alone under otherwise comparable reaction conditions. We then demonstrate that the nature of the Cu2-xS template dictates the final polymorph of the CZTS nanocrystal products. Through digenite, the cation exchange reaction readily yields the k-CZTS phase due to its highly similar anion sublattice. Covellite nanocrystals template the k-CZTS phase but via major structural rearrangement to digenite that requires elevated temperatures in the absence of a strong reducing agent. In contrast, we show that independently synthesized djurleite nanorods template the formation of the wurtzite polymorph (w-CZTS) but with prominent stacking faults in the final product. Applying this refined understanding to the standard one-pot syntheses of k- and w-CZTS nanocrystals, we identify that these reactions are each effectively templated by binary intermediates formed in situ, harnessing their properties to guide the overall synthesis of phase-pure quaternary materials. Our results provide tools for the careful development of tailored nanocrystal syntheses in complex polymorphic systems.

Evidence of Rate Limiting Proton Transfer in an SNAr Aminolysis in Acetonitrile under Synthetically Relevant Conditions.

An early synthetic step in the synthesis of adavosertib, AZD1775, is the SNAr reaction between 4-fluoronitrobenzene and 1-methylpiperazine in acetonitrile. A simple kinetics-based design of four reaction profiling experiments was used to investigate the kinetics of the reaction for the purpose of building a kinetic model. Fitting of the reaction profile data from two experiments conducted at 70 °C with a different excess of 1-methylpiperazine showed the reaction to follow a third-order rate law with a second-order dependence upon 1-methylpiperazine. This was rationalized in terms of the reaction following a rate-limiting proton transfer mechanism (base catalyzed) in which the progress to product is driven by a proton transfer involving a second molecule of 1-methylpiperazine. The experimentally determined entropy of activation of -180 J K-1 is consistent with this mechanism. The formation of a low level impurity was found to be due to the presence of traces of piperazine in the 1-methylpiperazine, which was shown to react approximately 15 times faster than 1-methylpiperazine at 70 °C. The rate constants for the 1-methylpiperazine catalyzed reaction of piperazine, 1-methylpiperazine, and the piperazine derived impurity were found to correlate in a Brønsted type analysis with the pKa's (acetonitrile) of the amine nucleophile.

Impact of A-Site Cation Deficiency on Charge Transport in La0.5-xSr0.5FeO3-δ.

The electrical conductivity of La0.5−xSr0.5FeO3−δ, investigated as a function of the nominal cation deficiency in the A-sublattice, x, varying from 0 to 0.02, has demonstrated a nonlinear dependence. An increase in the x value from 0 to 0.01 resulted in a considerable increase in electrical conductivity, which was shown to be attributed mainly to an increase in the mobility of the charge carriers. A combined analysis of the defect equilibrium and the charge transport in La0.5−xSr0.5FeO3−δ revealed the increase in the mobility of oxygen ions, electrons, and holes by factors of ~1.5, 1.3, and 1.7, respectively. The observed effect is assumed to be conditioned by a variation in the oxide structure under the action of the cationic vacancy formation. It was found that the cation deficiency limit in La0.5−xSr0.5FeO3−δ did not exceed 0.01. A small overstep of this limit was shown to result in the formation of (Sr,La)Fe12O19 impurity, which even in undetectable amounts reduced the conductivity of the material. The presence of (Sr,La)Fe12O19 impurity was revealed by X-ray diffraction on the ceramic surface after heat treatment at 1300 °C. It is most likely that the formation of traces of the liquid phase under these conditions is responsible for the impurity migration to the ceramic surface. The introduction of a cation deficiency of 0.01 into the A-sublattice of La0.5−xSr0.5FeO3−δ can be recommended as an effective means to enhance both the oxygen ion and the electron conductivity and improve ceramic sinterability.

Insight into BN Impurity Formation during Boron Nitride Nanotube Synthesis by High-Temperature Plasma.

The high-temperature plasma process has demonstrated great potential in growing high-quality boron nitride nanotubes (BNNTs) with small diameters (∼5 nm) and few walls (3–4 walls) and led to successful commercialization with a high production rate approaching 20 g/h. However, the process is still accompanied by the production of BN impurities (e.g., a-BN, BN shell, BN flakes) whose physicochemical properties are similar to those of BNNTs. This renders the post-purification process very challenging and thus hampers the development of their practical applications. In this study, we have employed both experimental and numerical approaches for a mechanistic understanding of BN impurity formation in the high-temperature plasma process. This study suggests that the flow structure of the plasma jet (e.g., laminar or turbulent) plays a key role in the formation of BN impurities by dictating the transport phenomena of BNNT seeds (e.g., B droplets), which play an important role in BNNT nucleation. We discussed that the turbulence enhances the radial diffusion of B droplets as well as their interparticle coagulation, which leads to a significant reduction in the population of effective BNNT seeds in the BNNT growth zone (T < 4000 K). This results in the generation of unreacted BN precursors (e.g., B-N-H species) in the BNNT growth zone that eventually self-assemble into BN impurities. Our numerical simulation also suggests that a higher thermal energy input makes the flow more turbulent in the BNNT growth zone due to the elevated velocity difference between the plasma jet and ambient cold gas. This finding provides critical insight into the process design that can suppress the BN impurity formation in the high-temperature plasma process.

Green synthesis of zinc oxide nanoparticles from camellia sinensis: Organic dye degradation and antibacterial activity

In this paper, we report to green synthesis of zinc oxide nanoparticles (ZnO NPs) from the plant extract (Camellia sinensis) by using the hot plat combustion method (HPCM). The XRD analysis validates that ZnO NPs have a hexagonal wurtzite structure, without the formation of any other impurity and secondary phases. FE-SEM images show the synthesis of zinc oxide includes spherical rods of ZnO NPs with the least size range of 10–20 nm and elements present in the biologically green synthesized ZnO NPs confirmed by EDAX mapping. Synthesized ZnO NPs photocatalytic activity was evaluated by degrading methyl orange (MO) dye and degradation of 80 % using 0.5 g ZnO NPs for 180 min irradiation time. Further, the antibacterial property of ZnO NPs was evaluated against two different strains of bacteria like Staphylococcus aureus and Escherichia coli; however, the antibacterial efficiency of ZnO NPs effective against E. coli compared to S. aureus.

A novel single-phase γ′ nanocrystalline coating with high resistance to oxidation and scale rumpling yet mitigated interdiffusion with the alloy substrate

Novel single-phase γ′ nanocrystalline coatings with and without Pt modification were developed on René N5 single-crystal superalloy to investigate their cyclic oxidation behaviors at 1100 °C and 1150 °C. Compared with conventional β-(Ni,Pt)Al coating, the γ′ nanocrystalline coatings, whether with Pt addition or not, prevailed in terms of inhibiting elements interdiffusion and surface rumpling. More importantly, Pt introduction was observed to further enhance oxidation performances of the γ′ nanocrystalline coating. The synergistic effect of nanocrystalline structure and Pt modification promoted to develop a highly purified alumina scale, preventing the formation of extensive Y-rich oxide impurities and avoiding the premature failure of TGO.

Structural analysis of pure PtCu3 nanoparticles synthesized by modified Polyol process

The development of effective multi-functional Pt-based nanoparticles (NPs) with enhanced activity, stability, and reduced cost for advanced applications still remains a challenge. In this study, Pt(acac)2 and Cu(OAc)2 metal precursors were reduced to form Pt-Cu NPs at 140 °C in ethylene glycol and sodium borohydride that is a secondary reducing agent in the modified polyol method. The x-ray diffraction (XRD) and Rietveld refinement analyses confirmed the face-centered cubic PtCu3 structure with the space groups of Fm3 ̅m and a lattice constant of a=b=c=3.6829 Å. The average crystal size was found to be 2.76 nm by Scherrer's formula. Scanning electron microscopy (SEM) images confirm the formation of monodisperse PtCu3 NPs with an average size of 8.04 nm within a narrow range of 5-13 nm. While energy-dispersive x-ray spectroscopy (EDS) analysis confirmed that the composition is formed of 26% Pt and 74% Cu atoms and XRD and EDS analyses were confirmed impurity, by-products, and oxidation free NPs formation.

Liquid-Phase Epoxidation of Propylene with H2O2 over TS-1 Zeolite: Impurity Formation and Inhibition Study

Liquid-Phase Epoxidation of Propylene with H₂O₂ over TS-1 Zeolite: Impurity Formation and Inhibition Study

Synthesis and magnetic properties of CuCr2S4 chalcospinel nanocrystals using single-source precursors

Magnetic thiospinel CuCr2S4 nanocrystals (NCs) have been synthesized via hot-injection (HI) method using metal-complexes of diethyl dithiocarbamate (DDTC) and 1-dodecanethiol (1-DDT) as the precursors. The single-source precursor's effect on the composition, crystallinity, and structure of the products is studied. Moreover, the influence of various process parameters, such as reaction time and temperature, capping ligand, and precursor on the crystalline phase, shape, and size of the NCs is systematically investigated. The morphological changes and magnetic properties of the NCs are also examined. The synthesized materials have been analyzed and characterized using X-ray diffraction, TEM, HRTEM, HAADF-STEM, and EDS-STEM. The results reveal the formation of uniform NCs of CuCr2S4 along with appearance of a trace amount of sulfur. The presence of sulfur in the structure of the organic ligand DDTC likely facilitates formation of the sulfur impurity. Our results indicate that controlling the formation of pure-phase nanoparticles using metal-DDTC precursors is more challenging than using simple metal salts reported earlier. Nevertheless, this work is the first successful effort in preparing NCs of CuCr2S4 employing single-source precursors.

Characterization of an Unknown Impurity in Indobufen Tablets by HPLC-Q-TOF MS and NMR

Background: Indobufen is a drug that hinders the aggregation of platelets by reversibly repressing the cyclooxygenase enzyme, further bringing about diminished thromboxane production. During quality control of indobufen tablets, an unknown impurity was detected. Objective: To characterize an unknown impurity in indobufen tablets. Methods: A new method compatible with mass spectrometry detection was set up. A C18 column at 35 °C with a mobile phase consisting of aqueous buffer (including ammonium formate) and methanol (35: 65, v/v) was used at a flow rate of 1.0 mL/min at 228 nm. High-performance liquid chromatography quadrupole time-of-flight mass spectrometry mass spectrometry (HPLC-Q-TOF MS) was used to identify the impurity with the electrospray ionization (ESI) source in the positive ionization mode. Results: The results of HPLC-Q-TOF MS analysis indicated that the protonated molecule ions [M + H]+ of the unknown impurity was at m/z 312. Preparative LC method was put into practice with a Prep- C18 column with a mobile phase consisting of water and methanol (20: 80, v/v) at a flow rate of 20.0 mL/min at 228 nm. The assignment of the 1D and 2D NMR signals was performed for the unknown impurity. In addition, possible formation of the novel impurity was also studied. Conclusion: An unknown impurity in indobufen tablets was characterized. The impurity was assigned as 2-(4-(1-hydroxy-3-oxoisoindolin-2-yl) phenyl) butanoic acid.

Does Simulated Porcelain Firing Influence Corrosion Properties of Casted and Sintered CoCr Alloys?

The aim of the study was to evaluate how heat processing used for dental porcelain firing influences the surface properties of sintered and casted CoCr alloy. Two CoCr alloys, Soft Metal LHK (milling in soft material and sintering) and MoguCera C (casting), were used for the study. The samples were examined using SEM–EDS before and after heat treatment. Next, corrosion examinations (Ecorr, jcorr, polarization curve, Ebr) were performed. Finally, the samples were evaluated under SEM. Based on the results, the following conclusions might be drawn: 1. Thermal treatment (porcelain firing) did not cause chemical impurities formation on the surface of CoCr alloy; 2. The sintered metal exhibited significantly higher corrosion resistance than the casted one due to its homogeneity of structure and chemical composition; 3. Heat treatment (porcelain firing) decreased the resistance of casted and sintered CoCr alloy to electrochemical corrosion. The reduction in corrosion resistance was significantly higher for the casted alloy than for the sintered alloy; 4. The corrosion resistance decrease might be due to an increased thickness and heterogeneity of oxide layers on the surface (especially for the casted alloy). The development of corrosion process started in the low-density areas of the oxide layers; 5. The sintered metal seems to be a favourable framework material for porcelain fused to metal crowns.

Ion Substitution Effect on Defect Formation in Two-Dimensional Transition Metal Nitride Semiconductors, AETiN2 (AE = Ca, Sr, and Ba).

A layered semiconductor, SrTiN2, has an interesting crystal structure as a two-dimensional (2D) electron system embedded in a three-dimensional bulk periodic structure because it has alternate stacking of a SrN blocking layer and a TiN conduction layer, in which the Ti 3dxy orbital forms the conduction band minimum (CBM) similar to the SrTiO3-based thin-film heterostructure. However, SrTiN2 has been reported to exhibit nearly degenerate conduction, but we reported that it would be due to the easy formation of nitrogen vacancies and oxygen impurities from air. In this paper, we extend the materials to family compounds, alkaline earth (AE) ion-substituted, AETiN2 (AE = Ca, Sr, and Ba), and investigated how we can suppress the defect formation by (hybrid) density functional theory calculations. All AETiN2 compounds possess thermodynamic stability in the wide nitrogen (N) chemical potential window. Especially, CaTiN2 is the most stable even against N-poor conditions. Unintentional carrier generation occurs due to the nitrogen vacancies (VN), oxygen substitution (ON), and hydrogen anion substitution (HN) at the nitrogen sites. The VN and HN impurities can be suppressed under N-moderate and N-rich conditions. The ON defect is easily formed in SrTiN2 and also in BaTiN2 under N-rich conditions, but its formation can be suppressed in CaTiN2. Present results suggest that high-purity CaTiN2 can be obtained under wider N chemical conditions, which would lead to the realization of the novel functional properties originating from Ti 3dxy 2D bands embedded in the bulk crystal structure.

Formation of Surface Impurities on Lithium-Nickel-Manganese-Cobalt Oxides in the Presence of CO2 and H2O.

Surface impurities involving parasitic reactions and gas evolution contribute to the degradation of high Ni content LiNixMnyCozO2 (NMC) cathode materials. The transient kinetic technique of temporal analysis of products (TAP), density functional theory, and infrared spectroscopy have been used to study the formation of surface impurities on varying nickel content NMC materials (NMC811, NMC622, NMC532, NMC433, NMC111) in the presence of CO2 and H2O. CO2 reactivity on a clean surface as characterized by CO2 conversion rate in the TAP reactor follows the order: NMC811 > NMC622 > NMC532 > NMC433 > NMC111. The capacity of CO2 uptake follows a different order: NMC532 > NMC433 > NMC622 > NMC811 > NMC111. Moisture pretreatment slows down the direct CO2 adsorption process and creates additional active sites for CO2 adsorption. Electronic structure calculations predict that the (012) surface is more reactive than the (1014) surface for CO2 and H2O adsorption. CO2 adsorption leading to carbonate formation is exothermic with formation of ion pairs. The average CO2 binding energies on the different materials follow the CO2 reactivity order. Water hydroxylates the (012) surface and surface OH groups favor bicarbonate formation. Water creates more active sites for CO2 adsorption on the (1014) surface due to hydrogen bonding. The composition of surface impurities formed in ambient air exposure is dependent on water concentration and the percentage of different crystal planes. Different surface reactivities suggest that battery performance degradation due to surface impurities can be mitigated by precise control of the dominant surfaces in NMC materials.