In 1751, Swedish chemist Axel Fredrik Cronstedt coined the name “nickel” after struggling to refine ores from the Kupfernickel mine — a stubborn metal that wouldn’t behave like copper. That early stubbornness hinted at chemical quirks that matter centuries later.
Nickel is more versatile than it first appears: its atomic number is 28 and it melts at 1,455°C, yet it reacts with a surprising set of elements to form oxides, sulfides, carbides, phosphides, alloys and silicides. These reactions drive corrosion behavior, alloy design, catalysis and semiconductor contacts, and they show up in stainless steel, NiSi contacts and Monel hardware.
Here I examine eight elements nickel reacts with and why each interaction matters in real-world applications.
Nonmetal Reactivity: Oxidation, Sulfidation, and Halogen Attack
Nickel’s reactions with common nonmetals control surface chemistry and long-term performance. In air or oxygen-bearing atmospheres it forms oxides; in sulfur-bearing gases it forms sulfides that can be brittle; and halogens such as chlorine can produce soluble or volatile nickel chlorides that attack passive films.
For an authoritative take on oxide chemistry and high-temperature behavior see ASM International, and for thermochemical data consult NIST tables at NIST.
1. Oxygen (O) — Oxidation and Oxide Formation
Nickel reacts with oxygen to form stable oxides such as NiO and higher oxides (sometimes reported as Ni2O3 under specific conditions), and those layers strongly influence both corrosion resistance and catalytic activity.
Oxide growth is noticeable long before the metal melts; thin protective scales can form at a few hundred degrees Celsius and oxidation rates accelerate with temperature (scale growth becomes significant above ~200–300°C in many air-exposed systems). At turbine-operating temperatures, controlled oxide mixes (chromia with some nickel oxide) help protect superalloy blades.
Nickel oxide also serves as a catalytic phase in hydrogenation and reforming catalysts, so the presence and stoichiometry of NiO matters for both protection and reactivity.
2. Sulfur (S) — Sulfidation and Sulfide Formation
Sulfur combines with nickel to form sulfides such as NiS and Ni3S2, compounds that tend to be brittle and electronically dissimilar from the parent metal. In high-temperature refinery environments, even parts-per-million H2S can cause surface sulfidation over time.
Typical sulfidation occurs in hydrocarbon processing units at elevated temperatures (several hundred degrees Celsius), where sulfur-bearing gases contact heated metal surfaces. Industrial guides document H2S concentrations and corrosion allowances for piping and reactors.
The practical consequence is twofold: sulfide scales can embrittle tubing and vessels, and sulfur poisons active catalyst sites, reducing hydrogenation and reforming performance in petrochemical units.
3. Chlorine (Cl) — Halogen Corrosion and Chloride Attack
Chloride ions attack passive films on nickel and nickel alloys, forming soluble chlorides or local chemistry that promotes pitting and stress-corrosion cracking. That localized attack is often far more damaging than uniform corrosion.
Pitting thresholds vary by alloy and environment, but seawater chloride is roughly 19,000 ppm (about 3.5% salt), and chloride concentrations as low as a few hundred ppm can trigger pitting in stressed or sensitized metals. In pickling, acid chloride media accelerates metal loss and requires tight process control.
Marine structures, chemical-processing equipment and pickling lines must account for chloride-driven failure modes even when using nickel-rich alloys.
Carbon and Phosphorus: Carbides, Phosphides, and Catalytic Roles
Carbon and phosphorus interact with nickel in ways that reshape surface phases and catalytic properties. Carbon can dissolve into nickel, form carbides under high-temperature processing, or deposit as coke on catalysts. Phosphorus forms phosphides that are useful catalytically but can reduce toughness in alloys.
4. Carbon (C) — Carbides, Dissolution, and Catalysis
Nickel interacts with carbon both as a dissolved solute and via carbide formation in certain conditions. Carburizing and chemical vapor deposition (CVD) operations at high temperatures (typical carburizing ranges are roughly 800–950°C) can alter surface chemistry and hardness.
In heterogeneous catalysis, supported Ni particles are classic hydrogenation and steam-reforming catalysts, but they’re prone to carbon deposition (“coking”), which blocks active sites. Catalyst formulations and operating conditions aim to limit coke by adjusting temperature, steam-to-carbon ratios, and promoters.
Operational examples include industrial steam-reforming for hydrogen production and nickel-based methanation catalysts where carbon management is a central reliability issue.
5. Phosphorus (P) — Phosphides and Their Effects
Nickel and phosphorus form phosphides such as Ni2P, phases that are prized as hydrodeoxygenation and hydrotreating catalysts in refining and biomass upgrading. Ni2P provides active sites for removing oxygen and sulfur from complex feeds.
At the same time, small amounts of phosphorus in structural alloys (even at ppm levels) can embrittle grain boundaries and reduce toughness, so metallurgists balance phosphorus for catalytic benefit against mechanical risk.
Practical cases include Ni2P catalysts used to upgrade bio-oils and refinery streams, while piping and pressure-vessel specifications limit phosphorus content to protect fracture resistance.
Metal-Metal and Semiconductor Reactions: Alloying and Silicide Formation
To understand the elements nickel reacts with in engineering contexts, look at iron, copper and silicon — each interaction defines entire product classes from stainless steel to CMOS contacts.
6. Iron (Fe) — Alloying in Stainless and Structural Alloys
Nickel and iron form continuous solid solutions and are the backbone of austenitic stainless steels. Common grades (304/316 family) typically contain about 8–12% nickel to stabilize the austenite phase and improve toughness and corrosion resistance.
Specialized stainless and superalloys can contain higher nickel fractions (some grades approach 20% Ni or more) to meet creep and corrosion requirements in chemical plants and turbines. Global stainless-steel production is on the order of tens of millions of tonnes annually (roughly 50 million tonnes in recent years), underscoring how widespread these Ni–Fe systems are.
Applications range from cookware and food-plant piping to high-temperature Ni–Fe–Cr-based superalloys in jet engines, where nickel’s presence changes phase stability and performance.
7. Copper (Cu) — Monel, Coinage Alloys, and Electrical Uses
Nickel and copper form useful alloys such as Monel and cupronickel that balance corrosion resistance with conductivity. Monel compositions commonly sit near 60–70% Ni with about 20–30% Cu, while cupronickel mixtures vary depending on seawater resistance needs.
These alloys perform admirably in marine environments, desalination heat-exchanger tubes and chemical valves; Monel fittings are standard where seawater corrosion is a concern. Nickel also improves strength and wear resistance in coinage and electrical contact alloys.
Designers pick Ni–Cu ratios to tune conductivity, corrosion resistance and mechanical behavior — small composition shifts have big practical effects.
8. Silicon (Si) — Nickel Silicides in Microelectronics
Nickel reacts with silicon to form nickel silicides (Ni2Si, NiSi, NiSi2), which are essential for low-resistance contacts in semiconductor devices. NiSi in particular became a go-to contact material during the 1990s–2000s because it forms at relatively low temperatures and provides good sheet resistance.
Typical rapid thermal anneal temperatures for NiSi formation are about 300–450°C, depending on process timing and environment. Controlling phase formation and minimizing junction consumption are key process metrics; target sheet-resistance values vary by node but NiSi helped meet aggressive contact-resistance budgets in past CMOS nodes.
Foundries used nickel silicide processes to replace earlier refractory contacts, trading process complexity for lower contact resistance and scalable thermal budgets.
Summary
- Nickel reacts with nonmetals like oxygen, sulfur and chlorine to form oxides, sulfides and chlorides that govern corrosion, high-temperature protection and catalyst behavior.
- Carbon and phosphorus shape surface phases and catalytic performance: carbon leads to carbides or coking in reformers, while Ni2P offers useful hydrotreating activity but can affect alloy toughness.
- Metal–metal reactions with iron and copper produce foundational engineering alloys (stainless steel, Monel, cupronickel) where a few percent nickel makes large property changes; reaction with silicon produces NiSi silicide contacts formed near 300–450°C for microelectronics.
- Practical takeaway: check material datasheets and service-environment specs (chloride levels, H2S ppm, operating temperatures) and consult corrosion or alloy experts before specifying nickel-containing materials.
