Sulfur Mobility Research Articles

One-pot Synthesis of High-capacity Sulfur Cathodes via In-situ Polymerization of a Porous Imine-based Polymer.

Lithium-ion batteries, essential for electronics and electric vehicles, predominantly use cathodes made from critical materials like cobalt. Sulfur-based cathodes, offering a high theoretical capacity of 1675mAhg-1 and environmental advantages due to sulfur's abundance and lower toxicity, present a more sustainable alternative. However, state-of-the-art sulfur-based electrodes do not reach the theoretical capacities, mainly because conventional electrode production relies on mixing of components into weakly coordinated slurries. Consequently, sulfur's mobility leads to battery degradation - an effect known as the "sulfur-shuttle". This study introduces a solution by developing a microporous, covalently-bonded, imine-based polymer network grown in-situ around sulfur particles on the current collector. The polymer network (i) enables selective transport of electrolyte and Li-ions through pores of defined size, and (ii) acts as a robust host to retain the active component of the electrode (sulfur species). The resulting cathode has superior rate performance from 0.1C (1360mAhg-1) to 3C (807mAhg-1). Demonstrating a high-performance, sustainable sulfur cathode produced via a simple one-pot process, our research underlines the potential of microporous polymers in addressing sulfur diffusion issues, paving the way for sulfur electrodes as viable alternatives to traditional metal-based cathodes.

Ein‐Topf‐Synthese von Schwefelkathoden mit hoher Kapazität durch In situ‐Polymerisation eines porösen Polymers auf Iminbasis

AbstractLithium‐Ionen‐Batterien, die für elektronische Geräte und Elektrofahrzeuge unerlässlich sind, verwenden hauptsächlich Kathoden aus kritischen Materialien wie Kobalt. Eine nachhaltigere Alternative sind Kathoden auf Schwefelbasis, die eine hohe theoretische Kapazität von 1675 mAh g−1 und Umweltvorteile bieten, da Schwefel reichlich vorhanden und weniger toxisch ist. Moderne Elektroden auf Schwefelbasis erreichen die theoretische Kapazität jedoch nicht, vor allem weil die herkömmliche Elektrodenherstellung auf dem Mischen der Komponenten zu schwach koordinierten Aufschlämmungen beruht. Infolgedessen führt die Mobilität des Schwefels zu einer Degradation der Batterie – ein Effekt, der als „Schwefel‐Shuttle“ bekannt ist. Diese Studie stellt eine Lösung vor, indem ein mikroporöses, kovalent gebundenes, iminbasiertes Polymernetzwerk entwickelt wird, das in situ um die Schwefelpartikel auf dem Stromkollektor wächst. Das Polymernetzwerk (i) ermöglicht den selektiven Transport von Elektrolyt und Li‐Ionen durch Poren definierter Größe und (ii) fungiert als robuster Wirt, um die aktive Komponente der Elektrode (Schwefelspezies) zurückzuhalten. Die resultierende Kathode hat eine überlegene Leistung von 0,1 C (1360 mAh g−1) bis 3 C (807 mAh g−1). Mit der Demonstration einer leistungsstarken, langlebigen Schwefelkathode, die in einem einfachen Eintopfverfahren hergestellt wurde, unterstreicht unsere Forschung das Potenzial mikroporöser Polymere bei der Lösung von Schwefeldiffusionsproblemen und ebnet den Weg für Schwefelelektroden als praktikable Alternative zu herkömmlichen Kathoden auf Metallbasis.

Influence of coverage on adsorbate diffusion measurements at electrode surfaces by in situ linear optical diffraction.

In situ linear optical diffraction is a new method for studies of surface mass transport in electrochemical environments that is based on the equilibration of coverage gratings in an adlayer on the electrode surface. We, here, discuss the temporal evolution of the diffraction intensity on the basis of experimental data for sulfur adsorbates on Pt(111) electrodes in 0.1M H2SO4 and simulations of the time-dependent diffusion profiles. At low and medium sulfur coverage, the decay of the signal exhibits two time scales, which can be explained by the influence of coverage-dependent diffusion rates on the evolution of gratings with large coverage modulation. At high coverage, a further ultra-slow decay process or even a complete termination of the decay is observed, which we attribute to the presence of high-density, ordered, adlayer phases with low sulfur mobility. These results provide insight into the approaches required for extracting quantitative surface transport rates from linear optical diffraction measurements.

Manipulating Sulfur Mobility Enables Advanced Li-S Batteries

Summary Rational design of lithium-sulfur batteries calls for enhancing local sulfur mobility and electrocatalysis while suppressing global sulfur mobility (GSM) from cathode to anode and within cathode without sacrificing volumetric or gravimetric capacities. A multifunctional interlayer composed of electrochemically active Mo6S8 with fast topotactic/intercalation reactions, strong lithium polysulfide binding, and high electronic conductivity addresses these challenges. The electrocatalytic LixMo6S8 interlayer successfully solves the harmful stratification by preventing the Li2S clogging at the cathode/separator interface, thus resulting in a superior rate capability up to 4 C. Remarkably, the LixMo6S8 interlayer works well with the calendered high-loading sulfur cathode with much improved volumetric energy density at a pouch-cell level. An excellent capacity retention with high initial capacity is also achieved with high-sulfur-loading cathode and lean electrolyte.

A Road Less Traveled: Trafficking Hydrogen Sulfide and B12

Similar in their very low intracellular abundance, the metabolism of hydrogen sulfide (H2S) and vitamin B12 intersect at the sulfur mobility in PPD network where B12 serves as a cofactor, and H2S spews from enzymes with relaxed specificity. While only two mammalian enzymes require B12 for activity, cells maintain a regiment of chaperones to tailor and escort B12 from its point of entry into the cell to its targets. During this inter‐compartmental voyage, B12 is translocated between active sites in transient protein‐protein complexes, which exhibit the artful use of coordination chemistry. Structural enzymology studies on trafficking proteins are providing molecular insights into the cellular strategies for moving this portly organometallic cofactor. While the metabolic activity of gut microbiota represents a limited source of B12, it is a substantial source of H2S and necessitates adaptations by host cells to routine exposure to this respiratory toxin. Our studies are revealing the metabolic reprogramming that is part of the stress response to H2S in colon epithelial cells. Thus, although low in abundance, B12 and H2S have profound impacts on cellular biochemistry.Support or Funding InformationNational Institutes of Health (DK45776, HL58984, GM112455)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Chinese knot-like electrode design for advanced Li-S batteries

Rational design of Li-S batteries requires efficient prevention of sulfur mobility and fast redox kinetics while accommodating the volumetric expansion of the sulfur cathode. Herein, we propose a multifunctional Chinese knot-like electrode design for advanced Li-S batteries. NiCo2S4 nanotubes are closely interwoven to form Chinese knot-like designs as a sulfur host. The unique interconnectivity of the 2D Chinese knot-like networks constructed by 1D nanostructured nanotubes enables fast electron transfer for high capacity. Furthermore, the hollow structure can simultaneously provide enough space for volumetric expansion of sulfur and confine lithium polysulfides (LiPSs) in the internal void space by structural encapsulation. Besides these, experimental and theoretical analysis demonstrates that NiCo2S4 can effectively capture the LiPSs and then catalyze the captured LiPSs into solid Li2S2/Li2S. More importantly, the transition between low-spin and high-spin of Co ions, induced by extra sulfur atoms from LiPSs, provides an electronic way to stabilize the adsorption system and reduce system energy, leading to the inhibition of the shuttle effect in Li-S batteries. As a result, the Chinese knot-like S@NiCo2S4 electrodes show a high capacity of 1348 mA h g−1 at 0.1 C and long cycling life up to 1000 cycles with a slow capacity decay of 0.02% per cycle at 1 C. Even with a higher sulfur loading of 5 mg cm−2, the electrodes still deliver good electrochemical performance.

γ-アルミナ担持および高表面積チタニア担持モリブデン，コバルト-モリブデン，ニッケル-モリブデン水素化脱硫触媒挙動の<sup>35</sup>Sトレーサー法に基づいた比較

The differences between MoS2, CoMoS and NiMoS HDS catalysts supported on γ-alumina and high SSA titania are investigated based on the results of [35S]DBT HDS experiments. Previous studies of MoS2 and CoMoS are reviewed, discussed and compared with new results for NiMoS. Introduction of Ni or Co to MoS2/Al2O3 catalysts classically yields a significant increase in HDS performance. Irrespective of the promoter, an increase in S0, the number of labile sulfur atoms, is observed. In contrast, kRE, the H2S liberation rate constant, plotted as a function of the Ni/Mo ratio, presents a volcano profile on Ni-promoted catalysts, but kRE reaches a plateau from low Co/Mo ratios on Co-promoted catalysts. The 'TiMoS' phase, which is formed in-situ during HDS on Mo/TiO2 catalysts, promotes sulfur mobility and makes Mo/TiO2 catalysts more active than Mo/Al2O3 catalysts. Nevertheless, CoMo/TiO2 catalysts are less active than CoMo/Al2O3 catalysts because further promotion of 'TiMoS' phase with Co might yield excessive weakening of the metal-sulfur bonds, and/or some Co atoms might be 'lost' in the TiO2 matrix without interacting with MoS2. In contrast, introduction of Ni to Mo/TiO2 catalysts yields significant increases in both kRE and S0. The NiMo/TiO2 catalysts exhibit HDS performances close to those of Al2O3-supported catalysts. Clearly catalytic behavior over Co- and Ni-promoted catalysts is different.

Investigation of sulfur behavior on CoMo-based HDS catalysts supported on high surface area TiO 2 by 35S radioisotope tracer method

Three series of CoMo catalysts (MoO 3: 6, 11, 16 wt.%) with various Co/Mo molar ratios were prepared by successive incipient wetness impregnations of a titania sample previously prepared by the pH swing method, which provides a TiO 2 carrier with a high SSA (134 m 2 g −1) and excellent mechanical properties. DBT HDS activity of the catalysts increased with addition of cobalt up to Co/Mo = 0.4 and then decreased for higher ratios, irrespective of the Mo loading. The results of a [ 35S]DBT HDS method showed that S 0, the amount of labile sulfur atoms, increased in parallel with the activity when adding Co up to a molar ratio of 0.4. In contrast, unlike on CoMo/Al 2O 3 catalysts, only a slight increase in k RE, the H 2S release rate constant, was observed upon Co addition. This was due to formation of the TiMoS phase: while formation of Ti S * Mo bonds favorably induces an increase in sulfur mobility on Mo/TiO 2 catalysts, electronic density on Mo atoms increases, which limits the promoting effect of Co on mobility of S a sulfur atoms bridged between Mo and Co. Further, while the increase in HDS activity upon Co addition on a uniform MoS 2 monolayer on TiO 2 was in rather good agreement with the quantitative and kinetics data of the 35S tracer method, over MoS 2 slabs on TiO 2 this increase was larger than that expected from the results of the 35S tracer method. This was attributed to the presence of □ * and □ a CUS, i.e. catalytic sites that are not replenished with sulfur, at the steady state. A larger number of □ * CUS was present at low Mo wt.% or for low Co/Mo. As these particular catalytic sites are in the form of CUS at the steady state, they are not accounted by the [ 35S] radiotracer method. This explains the differences observed between the experimental DBT HDS promotion and the promotion deduced from the increase in k RE and S 0.

Sulfur mobility in peat

Lead-210 chronologies, vertical S concentration gradients and δ 34S values are presented for 5 Sphagnum-dominated peat bogs located in Central Europe (Rybarenska slat and Ocean Bog; Czech Republic) and the British Isles (Thorne Moors, England; Connemara, Ireland; and Mull, Scotland). Sulfur concentrations were measured in three 40-cm deep peat cores per site, sectioned into 2-cm segments. The coefficient of variation in S concentrations was low across all depths and sites (mean of 16%), indicating a high degree of within-site homogeneity in vertical S patterns. Similar S concentration trends and similar δ 34S trends were found at all study sites. With an increasing peat depth, S concentrations first increased and then decreased. S concentrations peaked in layers which were deposited in ca. 1959, 1907, 1945, 1899 and 1799 at Rybarenska slat, Ocean, Thorne Moors, Connemara and Mull, respectively. Atmospheric S deposition peaked in 1972 in the UK and in 1987 in the Czech Republic. Due to downward S mobility in peat, S concentration maxima were found in layers 59 (±19) a older that the year of the actual peak in S input. With an increasing depth, the maturating peat substrate at all sites exhibited first a negative δ 34S shift, resulting from dissimilatory bacterial SO 4 reduction, and then a positive δ 34S shift, which may be related to advancing S mineralization. Minimum δ 34S values were detected in layers which were deposited in ca. 1988, 1982, 1945, 1940 and 1978. A comparison of historical δ 34S signatures of atmospheric S in England, measured on archived grain from the Broadbalk experiment (1845–1994), with δ 34S values of Thorne Moors peat (1830–1994) also indicated mobility of S in peat. Sulfur mobility in water-logged peat is of concern during the present period of easing industrial pollution because SO 4 released from peatlands may increase the acidity of the output.

Novel hydrodesulfurization catalysts derived from a supported rhodium carbonyl complex

Abstract The dibenzothiophene hydrodesulfurization (HDS) reactions were carried out over alumina, titania, silica and silica-alumina supported rhodium complex catalysts. First, a series of catalysts containing 1 wt.% Rh was prepared and tested. Whilst in the case of the Rh/Al 2 O 3 catalyst we did not observe any significant variation of the activity with the pretreatment, in the case of the titania, the silica and the silica-alumina supported catalysts, the pre-reduction treatment resulted in an activity twice as high as that obtained after the pre-sulfiding treatment. The use of the various supports slightly affected the overall HDS activity as well as the products selectivities. Whilst the Rh/Al 2 O 3 catalyst exhibited the highest biphenyl (BP) selectivity, the Rh/SiO 2 -Al 2 O 3 catalyst exhibited the highest dibenzothiophene conversion. The Rh supported on TiO 2 , SiO 2 and SiO 2 -Al 2 O 3 catalysts gave high cyclohexylbenzene (CHB) yields, indicating high hydrogenation abilities. Further, the effect of the Rh loading was studied on the titania and the silica supports. Unlike the other supports for which the activity stabilized for Rh loadings higher than 0.5–1.0 wt.%, the DBT conversions of the SiO 2 -supported Rh catalysts increased up to 4 wt.% Rh, exhibiting the highest HDS activity. To precisely elucidate the effect of the pre-activation method on the sulfidation state and on the HDS activity, the 4 wt.% Rh/SiO 2 catalyst was placed under HDS working conditions and [ 35 S ]DBT HDS tracer experiments were performed. We found that, whilst the amount of labile sulfur (S OA ) present on the surface of the prereduced catalyst was slightly lower than that observed for the presulfided catalyst, the labile sulfur atoms created on the prereduced catalyst exhibited a significantly greater mobility ( k RE ). This increase in sulfur mobility induced by the reduction pretreatment facilitated the active sites regeneration during the reaction, which led to an enhancement of the HDS catalytic activity.

Elucidation of promotion effect of cobalt and nickel on Mo/TiO2 catalyst using a 35S tracer method

Abstract A series of CoMo and NiMo catalysts supported on TiO 2 with various Co/Mo and Ni/Mo molar ratios were prepared to investigate the relationship between the nature of the support and the promotion effect of Co and Ni. The catalytic activities of these catalysts for the hydrodesulfurization (HDS) of dibenzothiophene (DBT) were measured. The HDS activity of CoMo/TiO 2 catalysts increased linearly with the addition of cobalt up to Co/Mo ratio of 0.6 and then decreased slightly above this value. Similarly, the HDS activity of NiMo/TiO 2 catalysts increased linearly with the addition of nickel up to Ni/Mo ratio of 0.6 and remained almost constant above this value. The sulfur mobility on the CoMo/TiO 2 and NiMo/TiO 2 catalysts under the reaction conditions was elucidated by a 35 S radioisotope tracer method using 35 S -labeled DBT. The amount of labile sulfur ( S 0 ) increased linearly with the addition of cobalt or nickel up to molar ratio of 0.6. In contrast, no significant difference in the rate constants of H 2 S release ( k RE ) was observed between Co- or Ni-promoted catalysts and non-promoted Mo catalysts at a given temperature. Therefore, the increase in catalytic activity with the addition of cobalt or nickel can be attributed to an increase in the number of active sites.

Elucidation of Behavior of Sulfur on Mo Catalysts Supported on TiO2 with Various Surface Areas Using 35S Tracer Methods

A series of Mo catalysts supported on TiO2 with various surface areas were prepared. In hydrodesulfurization (HDS) of dibenzothiophene (DBT) the activities of the series of catalysts were estimated. The results show that the activities of the series of catalysts increased linearly with the surface areas of TiO2 supports. The sulfur mobility on the sulfided Mo/TiO2 catalysts under the reaction conditions was elucidated by a 35S radioisotope tracer method using 35S-labeled DBT. The results suggest that the sulfur exchange rate constants (kRE) were approximately the same for all catalysts at a given temperature and that the amount of labile sulfur (S0) increases linearly with the surface area of TiO2 supports. The sulfidation states of the series of catalysts were also investigated by a 35S radioisotope pulse tracer method using 35S-labeled H2S. The results indicate that in spite of the coverage of Mo species on TiO2 support, the sulfidation of TiO2 support would still occur at 300°C. The sulfided catalysts could be reduced under H2 atmosphere.

Investigation of Cobalt Promotion on TiO2-supported Mo Catalysts Using a 35S Tracer Method.

A series of CoMo catalysts supported on TiO2 with various Co/Mo molar ratios were prepared to investigate the relationship between the support and the promoting effect of cobalt. The catalytic activities of these catalysts were measured for the hydrodesulfurization (HDS) of dibenzothiophene (DBT). The HDS activity of Mo/TiO2 catalysts increased remarkably with increased addition of cobalt up to Co/Mo ratio of 0.2 and then increased slightly above this value. The HYD activity of these catalysts remained almost constant with increasing Co/Mo ratio. Sulfur mobility on the sulfided CoMo/TiO2 catalysts under the reaction conditions was investigated by a 35S radioisotope tracer method using 35S-labeled DBT. The rate constants of H2S release (kRE) for Co-promoted catalysts were approximately the same as those for non-promoted Mo catalysts at a given temperature, indicating that the addition of cobalt did not affect the mobility of sulfur over Mo/TiO2 catalysts. In contrast, the amount of labile sulfur (S0) increased remarkably with the addition of cobalt up to Co/Mo ratio of 0.2 and then increased slightly above this value. The increase in the catalytic activity with the addition of cobalt is probably due to an increase in the number of active sites.

Elucidation of sulfidation state and hydrodesulfurization mechanism on Mo/TiO2 catalyst using [formula omitted] radioisotope tracer methods

In hydrodesulfurization (HDS) of dibenzothiophene (DBT) the activities on the Mo/TiO2 catalysts with various Mo contents were estimated under the typical HDS reaction conditions. The results show that the activities of the catalysts increased linearly with Mo content up to 6wt.% MoO3, which means that the monolayer dispersion of MoO3 on TiO2 support is maintained up to 6wt.% MoO3. The sulfidation states of MoO3/TiO2 catalysts were investigated using a 35S radioisotope pulse tracer method. The results showed that the sulfidation of TiO2 support would also occur. Moreover, the sulfur mobility on the sulfided 6% MoO3/TiO2 catalyst under the reaction conditions was elucidated by a 35S radioisotope tracer method using 35S-labeled DBT. The results suggested that, compared to Mo/Al2O3 catalyst, Mo/TiO2 catalyst showed a little higher amount of labile sulfur (S0) and about two times higher release rate constant of H2S (kRE), which indicated that higher mobility of sulfur was obtained on sulfided Mo/TiO2 catalyst.

Elucidation of sulfur mobility on Cr, Mo and W-based catalysts in hydrodesulfurization using a35S pulse tracer method

In hydrodesulfurization of radioactive35S-labeled dibenzothiophene catalyzed by CrO3/Al2O3, it was found that sulfur on sulfided CrO3/Al2O3 was more labile than those on MoO3/Al2O3 and WO3/Al2O3, while the amount of sulfur was less than that on MoO3/Al2O3.

Sulfur isotopic profile through the oceanic crust: Sulfur mobility and seawater-crustal sulfur exchange during hydrothermal alteration

Measurements of the abundance of anhydrite and pyrite veins and the distribution of alteration types in oceanic basement enable estimates of global mass and isotopic fluxes of sulfur during hydrothermal alteration of oceanic crust. Fluxes of 2.5 × 10 12 g/yr S (δ-34 S = 2.7%) from the volcanic section to seawater and 2.1 × 10 12 g/yr of seawater S (21%) into the crust result in an insignificant change in the S content of altered ocean crust. These are clearly second-order fluxes compared to the riverine input of S to the oceans and the output of sedimentary pyrite. Most of the anhydrite that forms in the high-temperature axial convection cell must later be dissolved at lower temperatures during off-axis circulation. The mean δ-34 S of altered oceanic basement is 0.9%, only slightly changed from the primary value of 0.1%. Unless S is preferentially mobilized from 34 S-rich sulfide deposits or mineralized zones, subduction of altered basaltic crust is unlikely to be the source of high δ 34 S values of arc volcanic rocks (∼4%), but could contribute to isotopic heterogeneities of S in the mantle.

Comparative Study of Sulfide Ni‐Mo Catalysts, Supported on y‐al2o3 and Activated Carbon by Using Radioisotope 35s

AbstractUsing radioactive Isotope 35S a comparative study of C‐ and Al2O3‐supported MoS2 catalysts promoted by Nl in hydrodesulfurization of thiophene has been performed. Ni content varied from O up to 3.5%. Promotion effect on thiophene conversion and catalyst sulfide sulfur mobility has been studied. C‐supported catalysts have been found to have higher catalytic activity than analogous alumina‐supported ones. Active site productivity in both C‐ and Al2O3‐supported catalysts is the same but the number of active sites in the former is larger than in the latter.

Investigation of the promotion effect on the sulfide sulfur mobility and on the catalytic activity of hydrotreating Co/Mo/Al2O3 catalysts using35S

Using S the effect of sulfur in Co/Mo/A12O3 catalysts on catalytic activity has been studied. A linear dependency between the amount of sulfur capable of participating in the formation of H2S and the catalytic activity has been established. It has been shown that with increasing the Co content, the overall amount of sulfide sulfur in the catalyst changes negligibly, while the amount of mobile sulfur increases linearly. It has been found that the promoter effects on the two groups of active sites that determine the sulfide sulfur mobility are different.

The sulfur induced reconstruction of the Pt(S)-[6(111)×(100)] surface

The sulfur induced reconstruction of the Pt(S)-[6(111)×(100)] surface to other stable structures was investigated using low energy electron diffraction and Auger electron spectroscopy. These reconstructed surfaces involve a doubling of the clean surface terrace width and step height. The conditions of annealing temperature and sulfur coverage leading to the reconstructions were determined from this study. The mechanism for the reconstruction is strongly dependent on the preferential adsorption of sulfur at the step edge, and the reconstruction occurs even for very small sulfur coverages. The observed nucleation of (2×2) and (√3×√3) R30° sulfur overlayers by the step edge at relatively low sulfur coverages further supports this conclusion. Observation of the LEED pattern in real time in the 200–300 °C temperature region indicates that the temperature dependence of the sulfur mobility on the surface defines the reconstruction time. Several possible mechanisms for the reconstruction process are discussed, and the ranges of stability of the various reconstructions are indicated.

Heavy metal and sulfur transport during subcritical and supercritical hydrothermal alteration of basalt: Influence of fluid pressure and basalt composition and crystallinity

Crystalline basalt, diabase and basalt glass have been reacted with a Na-Ca-K-Cl fluid of seawater ionic strength at 350–425°C, 375–400 bars pressure and fluid/rock mass ratios of 0.5–1.0, to assess the role of temperature, basalt/diabase chemistry and texture on heavy metal and sulfur mobility during hydrothermal alteration. Alteration of basalt/diabase is characterized by cation fixation and hydrolysis reactions which show increased reaction progress with increasing temperature at constant pressure. Correspondingly, pH in a series of 400 bar experiments ranges from 4.8 to 2.7 at 350 and 425°C, respectively and is typically lower for alteration of a SiO 2-rich crystalline basalt than for other rock types, due, in part, to relatively high SiO 2 concentrations in solution. High SiO 2 concentrations stabilize hydrous Na- and Ca-rich alteration phases, causing pH to decrease according to reactions such as: 3.0 CaAl 2 Si 2 O 8 + 1.0 Ca ++ + 2.0 H 2 O = 2.0 Ca 2 Al 3 Si 3 O 12( OH) + 2.0 H + Phases experimentally produced include: mixed layer chlorite/smectite, Ca-rich amphibole and clinozoisite. Clinozoisite was identified as a replacement product of plagioclase from diabase-solution interaction experiments. In direct response to H + production, dissolved Fe, Mn and H 2S concentrations increase dramatically. For early-stage reaction, H 2S typically exceeds Fe and Mn. However, at 425°C and after long-term reaction at 400°C, H 2S is lost from solution, apparently in response to pyrite replacement of oxide and silicate phases. Pyrrhotite formed at temperatures ≤ 375° C, whereas magnetite was identified in all run products, except from basalt glass alteration. Cu and Zn concentrations in solution are not simple functions of pH. These metals achieve greatest solubility in fluids from experiments at 375–400°C, except when basalt glass is used as a reactant. The relatively low concentrations of these species in solution during basalt glass reaction may be due to adsorption by fine grained alteration phases.