Redistribution Of Cu Research Articles

Morphological Characteristics of W/Cu Composite Nanoparticles with Complex Phase Structure Synthesized via Reactive Radio Frequency (RF) Thermal Plasma

The W/Cu binary system is characterized by its mutual insolubility and excellent wettability, making W/Cu composite materials ideal for managing thermal and electrical properties in electronic components. To optimize material properties, control over the microstructure is crucial, and nanocomposites with uniform dispersion offer significant advantages. In this study, W/Cu composite nanoparticles were synthesized by feeding a blended feedstock of tungsten trioxide (WO3) micro-powder and cupric oxide (CuO) micro-powder into a reactive radio frequency (RF) argon–hydrogen thermal plasma system. Cu-coated W nanocomposite particles were obtained through the vaporization, reduction, and condensation processes. The resulting nanocomposite particles were composed of body-centered cubic (BCC) α-W, A15 β-W, and face-centered cubic (FCC) Cu phases, with a chemical composition closely matching theoretical calculations. The phase evolution and morphological changes of the synthesized particles were analyzed as a function of heat treatment temperatures up to 1000 °C in a reducing atmosphere. Up to 600 °C, the phase composition and morphology remained stable. At 800 °C, localized diffusion and coalescence of Cu led to the formation of particulate Cu, and a significant phase transformation from metastable β-W to α-W was observed. Additionally, extensive Cu segregation due to long-range diffusion resulted in distinct Cu-rich and Cu-depleted regions. In these regions, notable sintering of W particles and the complete disappearance of β-W occurred. The results showed that the temperature-dependent redistribution of Cu plays a crucial role in the phase transformation of W and the morphology of W/Cu composite particles.

Optimizing temperature coefficient of Sm2Co17-type magnets through adjusting the isothermal aging process

The high-temperature magnetic performance and microstructure of Sm1–xGdx(CobalFe0.09Cu0.09Zr0.025)7.2 (x = 0.3, 0.5) magnets were investigated. With the isothermal aging time decreasing from 11 to 3 h, the temperature coefficient of intrinsic coercivity in the temperature range of 25–500 °C, β25–500 °C, was optimized from −0.167%/°C to −0.112%/°C for x = 0.3 magnets. The noticeable enhancement (∼33%) of temperature stability is correlated with the increased content of 1:5H cell boundary phase and its relatively high Curie temperature as well. However, for the x = 0.5 magnet, it is found that the presence of Sm5Co19 phases and wider nanotwin variants hinder the formation of 1:5H cell boundary phase. The insufficient 1:5H is not beneficial to the proper redistribution of Cu in cell boundary, making the x = 0.5 magnet difficult to achieve higher temperature stability. Consequently, the approach of adjusting the isothermal aging process can offer guidance for attaining superior magnetic performance in the temperature range from 25 to 500 °C for Gd-substituted Sm2Co17-type magnets.

Localized corrosion evolution associated with intermetallic particles in Al-Cu-Li alloys

Microstructure and corrosion behaviour associated with intermetallic particles (IMPs) in 2A97 Al-Cu-Li alloys of different thermomechanical conditions are characterized by a wide range of electron microscopy techniques in the present work. Three distinctive corrosion phenomena associated with IMPs are observed, including trenching, de-alloying and Cu re-distribution. Micro-galvanic interaction between IMPs and the peripheral matrix results in trenching, which may develop unevenly depending on stored energy distribution. Selective dissolution of more active elements also occurs to IMPs, which may result in de-alloyed bands related to stacking faults. The de-alloyed remnants further promote the re-distribution of Cu, which not only benefits the propagation of trenching, but may also contribute to the initiation of stable localized corrosion.

Effects of Biochars Derived from Sewage Sludge and Olive Tree Prunings on Cu Fractionation and Mobility in Vineyard Soils over Time

Copper-contained products that are widely employed yearly in viticulture for vine disease management, lead to Cu accumulation in topsoil creating an increased risk for land workers and for leaching and/or uptake of Cu by plants, especially in acidic soils where Cu mobility is higher. In this study, the impact of two biochar types on Cu distribution and redistribution in fractions was evaluated in four acidic vineyard soils in relation to incubation time. The two biochars were derived from sewage sludge (SG) and olive tree prunings (OL). Soils (control) and biochar-amended soils with application rate of 20 % (w/w) were spiked with CuCl2 (160 mg kg−1) and incubated in the laboratory at ambient temperature 22 ± 5 °C. After 1, 3, 7, 15, 36, and 90 days of incubation, modified BCR sequential extraction procedure was used to determine Cu distribution in the four soil chemical phases and to examine potential Cu redistribution between these fractions both in soils and in amended soils with biochars. Results show that biochar amendment affects Cu distribution in different soil fractions. In SG treatment, from the 1st and up to 36th incubation day, both exchangeable and reducible Cu fractions decreased, while oxidizable Cu increased, in relation to control soils. At 90th incubation day, a redistribution of Cu was observed, mainly from the oxidizable to the residual fraction. In OL treatment, during the first 36 incubation days exchangeable and oxidizable Cu slightly increased, while reducible Cu decreased. At the 90th incubation day the higher percentage of Cu was extracted from the residual fraction, but exchangeable Cu was present in remarkable quantities in the three of the four studies soils. SG application in the studied soils highly restricted the availability of added Cu promoting Cu-stable forms thus reducing the environmental risk while OL did not substantially reduce Cu available fraction over the experimental incubation period. Fourier transformation infrared analysis (FTIR) provided convincing explanations for the different behavior of the two biochar types.

Effective CO2 electroreduction toward C2H4 boosted by Ce-doped Cu nanoparticles

• An effective strategy has been established by doping Ce into Cu NPs to tune the electronic state of Cu. • It attains the faradaic efficiency of C 2 H 4 as high as 53% with a current density of 150 mA/cm 2 . • Such performance is about 2.8-fold increase when compared with Cu NPs. • The electronic structure regulation and defective sites facilitate highly efficient C 2 H 4 production from CO 2 electroreduction. Coupling another metal element tends to produce catalytic controls of high activity and selectivity. However, this action is still poorly explored to improve the selectivity of the electroreduction of CO 2 to C 2 H 4 with high energy density. Herein, Ce-doped Cu nanoparticles (Ce-Cu NPs) are synthesized by one-step co-reduction method and presented a preferable example that promotes selective transformation of CO 2 to C 2 H 4 in a flow-cell configuration. Thereinto, high faradaic efficiency (FE) of C 2 H 4 for Ce-Cu-2 NPs could reach 53% with the current density of 150 mA cm −2 , which is 2.8 times higher than that of Cu NPs. The outstanding performance mainly stems from tailoring the doped-Ce content shrinks particle sizes and forms oxygen defects due to the electron effect of nearby Ce atoms, boosting local electronic re-distribution of Cu. Meanwhile, in-situ Raman spectroscopies evidenced that the doping of Ce can enhance Cu site to bond *CO, which were beneficial to C–C coupling and thus endowed the catalyst with the superior catalytic performance in CO 2 electroreduction toward C 2 H 4 .

Immobilization pathways of heavy metals in composting: Interactions of microbial community and functional gene under varying C/N ratios and bulking agents

Excessive heavy metals (HMs) in livestock manure due to additives over-use limits its recycling through composting. However, few studies have investigated the interactive influence of microbial communities, functional genes, and environmental factors in HM immobilization during composting. Therefore, treatments with different C/N ratios (15:1, 20:1, 25:1) and bulking agents (maize straw, green waste, vinasse) were conducted to explore the HMs immobilization pathways using structural equation model (SEM). Results confirmed the promoting effect of C/N ratio of 20:1 and vinasse on microbial diversity, thus leading to greater HMs immobilization rate. Meanwhile, the dominant microbial phyla of Cu/Zn, Cd, As, and Cr were identified as Proteobacteria, Firmicutes, Chytridiomycota, and Bacteroidota, respectively. Moreover, the significant correlation between functional genes (copC, mt, cbh1, aoxB, yieF) and HMs illustrated potential immobilization effects of metal-binding proteins on Cu and Zn, humus complexation on Zn, and oxidase/reductase on As/Cr. Finally, SEM indicated that the redistribution of Cu, Zn, As, and Cr fractions was interactively influenced by environmental factors (organic matter, pH, electrical conductivity, and total phosphorus), microbial communities, and functional genes, while Cd was directly regulated by organic matter and total phosphorus. These results may provide a deeper understanding of HM immobilization pathways during swine manure composting.

Effect of inorganic additives (rock phosphate, PR and boron waste, BW) on the passivation of Cu, Zn during pig manure composting

The bioavailability of heavy metals in compost is critical for their agronomic value. The effect of inorganic additives (rock phosphate, PR and boron waste, BW) on Copper (Cu) and Zinc (Zn) bioavailability during co-compost of swine manure and rice straw was assessed using sequential extraction procedure (European Community Bureau of Reference). The result showed that both additives, applied at rates of 2.5%–7.5% (w/w) could promote the change of exchangeable Cu and reducible Cu into oxidizable Cu, thereby reducing their bioavailability factor (BF) by 15.5%–47.2%. While additives provided no significant reduction in BF of Zn, the shift from exchangeable Zn into reducible Zn can still reduce the mobility of Zn. Based on redundancy analysis (RDA), organic matter (OM) and electrical conductivity (EC) were identified as the most important controlling factors for redistribution of Cu and Zn fractions during composting. The inorganic additives strengthened the passivation of Cu and Zn bioavailability by stimulating OM degradation. The 7.5% (w/w) rock phosphate showed best passivating effect on the bioavailability of Cu.

Organic matter, a critical factor to immobilize phosphorus, copper, and zinc during composting under various initial C/N ratios

The status of heavy metals and the P fractions in compost affects their environmental risk. The present study investigated the effects of different initial carbon to nitrogen (C/N) ratios (15, 22, 27) on redistribution of Cu, Zn, and P fractions during composting. The results showed that the composting process transformed Cu, Zn and P from mobile fractions to more stable fractions. Compost with an initial C/N of 22 showed the most effective immobilization of Cu, Zn and P because of yielding greatest degree of polymerization. Multivariate statistical analysis identified organic matter as the most critical factor for explaining the redistribution of Cu, Zn, and P fractions in composting. However, the degree of organic matter degradation (organic matter content and Humic acid/Fulvic acid) better explained the change of bioavailability factor for Cu and the mobility of P during composting. This research provided guidance for providing technology to reduce environmental risk in compost.

OsATX1 Interacts with Heavy Metal P1B-Type ATPases and Affects Copper Transport and Distribution.

Copper (Cu) is an essential micronutrient for plant growth. However, the molecular mechanisms underlying Cu trafficking and distribution to different organs in rice (Oryza sativa) are poorly understood. Here, we report the function and role of Antioxidant Protein1 (OsATX1), a Cu chaperone in rice. Knocking out OsATX1 resulted in increased Cu concentrations in roots, whereas OsATX1 overexpression reduced root Cu concentrations but increased Cu accumulation in the shoots. At the reproductive stage, the concentrations of Cu in developing tissues, including panicles, upper nodes and internodes, younger leaf blades, and leaf sheaths of the main tiller, were increased significantly in OsATX1-overexpressing plants and decreased in osatx1 mutants compared with the wild type. The osatx1 mutants also showed a higher Cu concentration in older leaves. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that OsATX1 interacts with the rice heavy metal P1B-ATPases HMA4, HMA5, HMA6, and HMA9. These results suggest that OsATX1 may function to deliver Cu to heavy metal P1B-ATPases for Cu trafficking and distribution in order to maintain Cu homeostasis in different rice tissues. In addition, heterologous expression of OsATX1 in the yeast (Saccharomyces cerevisiae) cadmium-sensitive mutant Δycf1 increased the tolerance to Cu and cadmium by decreasing their respective concentrations in the transformed yeast cells. Taken together, our results indicate that OsATX1 plays an important role in facilitating root-to-shoot Cu translocation and the redistribution of Cu from old leaves to developing tissues and seeds in rice.

OsYSL16 is Required for Preferential Cu Distribution to Floral Organs in Rice.

Deficiency of copper (Cu) causes low fertility in many plant species, but the molecular mechanisms underlying distribution of Cu to the floral organs are poorly understood. Here, we found that a member of yellow-stripe like (YSL) family, YSL16 encoding the Cu-nicotianamine (Cu-NA) transporter, was highly expressed in the rachilla, with less expression in the palea and lemma of rice (Oryza sativa). β-Glucuronidase (GUS) staining of transgenic rice carrying the OsYSL16 promoter-GUS showed that OsYSL16 was mainly expressed in vascular bundles of the rachilla as well as the palea and lemma. Knockout of OsYSL16 resulted in decreased Cu distribution to the stamens, but increased distribution to the palea and lemma. A short-term (24 h) 65Cu labeling experiment confirmed increased Cu concentration of palea and lemma in the mutant. Furthermore, we found that redistribution of Cu from the palea and lemma was impaired in the osysl16 mutant after exposure to Cu-free solution. The osysl16 mutant showed low pollen germination, but this was rescued by addition of Cu in the medium. Our results indicate that OsYSL16 expressed in the vascular bundles of the rachilla is important for preferential distribution of Cu to the stamens, while OsYSL16 in vascular bundles of the palea and lemma is involved in Cu redistribution under Cu-limited conditions in rice.

A cost-effective approach to reducing carbon deposition and resulting deactivation of oxygen carriers for improvement of energy efficiency and CO2 capture during methane chemical-looping combustion

The objective of this research is to investigate the effect of steam on reducing carbon deposition during CH4 chemical looping combustion (CLC) on a fixed bed reactor. Steam proved to be significantly effective not only for the fuel utilization efficiency of CLC but also for the stability of the oxygen carrier (OC). The evaluation tests were performed with CuO/γ-Al2O3 OCs prepared with three different methods. The results showed that OC prepared using co-precipitation method performed the best with the highest reactivity for CH4 combustion at low temperature (700°C) compared to that prepared using mechanical mixture and impregnation methods. It was also found that the carbon deposition was the main reason for the low combustion efficiency and the deactivation of OCs in redox cycles. For OCs at 800°C, after 10 cycles without steam, 25–44% CO2 selectivity reductions were observed, accompanied by Barrett-Joyner-Halenda (BJH) pore volume decreases of 31–47%. With the steam introduction, the CO2 selectivity consistently achieved ∼100% in 10-cycle CLC, and the pore volumes of OCs decreased by only 11–22%, which was mostly attributed to the carbon-steam gasification reaction. The OCs for CH4 CLC with and without steam were characterized by using different methods, including surface area and pore analysis, thermal gravimetric analysis (TGA), X-ray diffraction (XRD), H2 temperature programming reduction (TPR), and scanning electron microscope (SEM). The results demonstrated that steam could easily gasify the carbon deposition, greatly intensify the redox degree of OCs at 800°C, and strengthen the redistribution of Cu on the surface of Al2O3, contributing to the fine and uniform distribution of CuO. Therefore, steam can be successfully used for considerable enhancement of the overall performance of CH4 CLC.

Homeostatic regulation of copper in a marine fish simulated by a physiologically based pharmacokinetic model

Copper (Cu) is an essential yet potentially toxic metal, thus delicate homeostatic controls are developed in the fish. In this study, a physiologically based pharmacokinetic (PBPK) model was developed to simulate the homeostatic regulation of Cu in a marine fish (Terapon jarbua) under dietary and waterborne exposures. In this model, fish were schematized as a six-compartment model, with the intestine being divided into two sub-compartments (chyme and gut wall). The blood was assumed to be the “carrier” distributing Cu into different compartments. The transfer rates between different compartments were determined in fish during Cu exposure (20 d) and depuration (20 d). The differences in Cu transfer from chyme to gut wall between dietary and waterborne treatments suggested that the intestine regulated the dietary uptake and re-absorption of Cu from the chyme. The extremely low uptake rate constant (0.0013 d−1) for gills under waterborne exposure indicated that gills strongly restricted Cu uptake from the ambient water. For both treatments, the liver had considerable input rate through the enterohepatic circulation and comparably high exchange rate with the blood, suggesting that the liver can efficiently accumulate newly absorbed Cu. The differences in Cu output from the liver between dietary and waterborne treatments suggested that it can effectively regulate the redistribution of Cu. All of these observations demonstrated that the liver played the central role in Cu homeostasis by serving as the main depository and distributing center. Modeling results also indicated that renal and branchial excretion was of minor importance, whereas biliary excretion combined with defecation played the most important role in whole-body Cu elimination in marine fish. The effective regulation by the “Blood-Liver-Intestine” cycle could be the main reason for the relatively low levels of Cu in fish.

Leaching and redistribution of Cu and Pb due to simulated road runoff assessed by column leaching test, chemical analysis, and PHREEQC modeling

In this study, column leaching with artificial road runoff experiments was conducted for 30 days under intermittent leaching. The heavy metal content and partitioning in the soil used in columns were characterized before and after the leaching experiments. A leaching model, PHREEQC, was used to simulate the metal speciation changes during leaching. A large portion of Cu and Pb were leached out with ARR at the early leaching stage and a slow decrease then occurred of the metal leaching toward the end of leaching period. The content of Cu and Pb associated with the oxidizable fraction (organic and sulfide bound metals) was decreased, while the content of metals associated with carbonate fraction increased by about twofold for Pb and threefold for Cu. Geochemical modeling demonstrated that Pb speciation may be dominated by carbonate in the leached soil. Geochemical modeling also indicated that the solution was under saturated with respect to the alite, calcite, and huntite mineral phases, while carbonate minerals such as annite and cerussite, and muscovite controlled the leachability of the metals.

New perspective on the performance stability of CdTe solar cells

Cu is a well-known cause for degradation of CdTe solar cells, yet, the exact mechanisms remain subject of discussion. We have chosen a novel approach to study CdTe solar cell stability by preparing CdTe solar cells in substrate configuration and applying a minimum amount of Cu to CdTe after recrystallization. These cells were exposed to an accelerated stress test. After 1000h of operation at maximum power point under 1 sun illumination intensity at 80°C substrate temperature such devices showed 90% of their initial power output indicating good performance stability. In order to investigate the remaining degradation and understand the role of Cu the Cu distribution in the multilayer stack was analyzed by SIMS before and after accelerated stress testing. We found that neither Cu loss in the back contact nor Cu accumulation in the CdS layer, which are often associated with degradation of CdTe solar cells, occurred in our case. C–V measurements revealed a decrease in net acceptor concentration by 70% and SCAPS simulations confirmed that this decrease can fully explain the observed performance losses of the solar cells. Time resolved photoluminescence measurements are consistent with the assumption that net acceptor loss upon stress is caused by a decay of acceptor type defects rather than by the formation of compensating donors. Acceptor loss can be explained by a redistribution of Cu inside the CdTe layer, possibly from within the grains to grain boundaries. The results demonstrate that by the use of a suitable Cu doping process that reduces Cu content at the back contact efficiency degradation due to Cu redistribution from back to front contact can be overcome. However, the observed acceptor loss appears in either configuration and seems to be independent of Cu movement from back to front or vice versa.

The comparison of the migration and transformation behavior of heavy metals during pyrolysis and liquefaction of municipal sewage sludge, paper mill sludge, and slaughterhouse sludge

Municipal sewage sludge, paper mill sludge, and slaughterhouse sludge were pyrolyzed and liquefied for the production of bio-char. The migration and transformation behavior of Cu, Cr, and Zn during pyrolysis and liquefaction of these sludges were studied. Pyrolysis and liquefaction promoted mobile fraction (F1 and F2) to stable fraction (F3 and F4). The results showed that pyrolysis and liquefaction largely affected the redistribution of Cu and Zn in raw materials. The environmental risk assessment results indicated that the environmental risk levels of Cu and Zn were significantly reduced in bio-char, and risk level of Cr was slightly decreased after pyrolysis or liquefaction. Both pyrolysis and liquefaction were promising detoxification technologies for the three sludges in terms of the mitigation of heavy metals toxicity. It was suggested that dewatered sludge could be reduced toxicity/risk before utilization by pyrolysis or liquefaction technology, especially for Cu and Zn in slaughterhouse sludge.

Decreased Copper Concentrations But Increased Lysyl Oxidase in Rhesus Monkey Model of Myocardial Ischemic Infarction

Ischemic injury leads to collagen deposition in the heart. Lysyl oxidase (LOX), a copper (Cu) dependent enzyme, catalyzes cross-linking of collagens. The present study was to investigate the relationship between Cu concentrations and LOX activities in the heart of ischemic infarction. Rhesus monkeys were subjected to coronary artery ligation, developing ischemic infarction. At 8 weeks after the surgery, monkeys were sacrificed and the molecular changes in the hearts were determined by Western blot, polymerase chain reaction (PCR), LOX enzyme activity, and atom absorption spectrometry (AAS). Collagen deposition was detected by hematoxylin and eosin (HE) staining, Masson's staining, and immunohistochemistry. Both type I and III collagen mRNA levels were increased along with increased fibrosis LOX protein levels and enzyme activities were significantly increased. However, Cu concentrations were significantly decreased Thus the increase in the Cu-dependent LOX activity with the decrease in the total Cu concentrations would predict a redistribution of Cu under ischemic condition, leading to enhanced collagen deposition. This study is supported by National Science Foundation of China (81300109).

Using synthetic models to simulate aging of Cu contamination in soils.

The Bureau Commun de Référence (BCR) sequential extraction scheme and micro-synchrotron-based X-ray fluorescence (μ-SXRF) analysis were used to determine the Cu fractionation in a calcareous vineyard soil and a synthetic soil (mixture of seven constituents: calcite, birnessite, ferrihydrite, goethite, lignocellulosic residue, kaolinite, and quartz) at different Cu contamination rates (190, 1270, and 6350 mg kg(-1) of Cu) and aging times (1, 30, 92, and 181 days). The Cu distribution in the spiked vineyard and synthetic soils was different from the original vineyard one and was influenced by the loading level. The newly added Cu was preferentially present in the acid soluble fraction. Aging of the contaminated vineyard and synthetic soils during 6 months led to the redistribution of Cu from the weakly bound acid soluble fraction to the strongly bound reducible one. The evolution with time could satisfactorily be simulated by the Elovich diffusion model for the synthetic soils. It was less significant as less marked in the contaminated vineyard soil than in the synthetic one, even though the trends observed in both were similar. This study supported the hypothesis that "simple" synthetic models could be used to approach the Cu fractionation and its evolution with time in vineyard soils.

Copper dynamics under alternating redox conditions is influenced by soil properties and contamination source

Understanding the effect of soil redox conditions on contaminant dynamics is of significant importance for evaluating their lability, mobility and potential transfer to other environmental compartments. Under changing redox conditions, soil properties and constituents such as Fe and Mn (hydr)oxides and organic matter (OM) may influence the behavior of associated metallic elements (MEs). In this work, the redox-driven release and redistribution of Cu between different soil pools was studied in three soils having different contamination sources. This was achieved by subjecting soil columns to a series of alternating reducing and oxidizing cycles under non-limiting C conditions, and assessing their influence on soil pore water, leachate and solid phase composition. Results showed that, in all soils, alternating redox conditions led to an increase in the distribution of Cu in the more labile fractions, consequently enhancing its susceptibility to loss. This was generally linked to the redox-driven cycling of Fe, Mn and dissolved organic matter (DOM). In fact, results suggested that the reductive dissolution of Fe and Mn (hydr)oxides and subsequent reprecipitation as poorly-ordered phases under oxic conditions contributed to the release and mobilization of Cu and/or Cu-containing organometallic complexes. However, the behavior of Cu, as well as the mechanisms controlling Cu release and loss with redox cycling, was influenced by both soil properties (e.g. pH, contents of easily reducible Fe and Mn (hydr)oxides) and source of Cu contamination.

Copper Dynamics in a Typic Hapludalf Under Rice-Wheat Cropping System After Twelve Years of Annual Lantana Camara L. Residue Incorporation

Long term effects of lantana (Lantana camera L.) residue and fertilizer application were studied on copper (Cu) fractions in a Typic Hapludalf under rice-wheat cropping at Palampur, India (32°6′N, 76°3′E). A partitioning of soil Cu revealed residual Cu and organically bound Cu as the most dominant fractions followed by Cu occluded by free oxides, specifically exchangeable Cu and soil solution and exchangeable Cu. Continuous incorporation of lantana after 12 years resulted in redistribution of Cu from non-available forms to readily and potentially available forms in soil. All the Cu fractions were positively interrelated amongst themselves and with grain yield and Cu uptake in rice and wheat crops. Specifically exchangeable Cu followed by organically bound Cu were the most important Cu fraction contributing towards grain yield and Cu uptake in rice and wheat crops.

Chemical imaging of the sulfur-induced deactivation of Cu/ZnO catalyst bodies

The effects of sulfur poisoning on the water–gas shift (WGS) activity of industrial Cu/ZnO/Al2O3 catalyst bodies have been studied. The samples were characterized using chemical imaging methods, including XRD-CT, XAFS mapping, and XRF, in order to understand the process by which accelerated sulfur poisoning leads to catalyst deactivation. After ∼90h on stream, all catalysts exhibited reduced activity; the higher the H2S concentration, the greater the extent of deactivation. Non-invasive XRD-CT measurements performed on intact samples recovered from the reactor revealed the formation of sulfide phases, including sphalerite (β-ZnS) and crystalline CuS, Cu2S, and CuSO4 phases. These sulfide phases were distributed predominantly as a graduated corona around the sample edge reaching ∼1.5mm thick for experiments performed in the highest concentration of 500ppm H2S. XAFS mapping, which is particularly sensitive to the local coordination environment around the element being probed, confirmed the presence of mixed Cu/Zn–O/S coordination environments and that the core of the sample remained sulfur-free. A combination of XRD-CT and XRF revealed that CuS appeared to be mobile under reaction conditions resulting in the redistribution of Cu toward the very edge of the samples. A combination of techniques has therefore demonstrated that H2S deactivation of Cu/ZnO/Al2O3 catalyst bodies occurs via phase transformation of the active Cu/ZnO phase into sulfides and redistribution of these components over the sample instead of Cu active site poisoning by Sads species.