Protactinium

Protactinium (Pa) — 10-Year Trends

As of 2026-09-11 · the last 10 years

Research intensity has held steady at roughly 9% of the element's all-time peak, a level that has remained flat over the past decade.

Research intensity ran from about 11% of the element's own all-time peak in 2016 to about 9% in 2026 — essentially flat across the window, and the all-time peak (1967) lies before this window. Over the same span its share of research attention across all elements held steady. Among the 118 elements, protactinium has one of the smaller research literatures of any element.

The number of papers involving the element rose from about 77 in 2016 to about 107 in 2025 (1.39x). That is slower than the literature as a whole grew over the same years, so the element lost ground in the wider body of research even as its own count rose.

The core of protactinium’s recent research is found in Protactinium Mono-oxo Cation Stability and Electronic Structure, a subcommunity within actinide chemistry. These papers use first-principle calculations to investigate the stability and electronic properties of the protactinium mono-oxo cation, with distinctive focus on cation probed and mono-oxo cation structures. Protactinium is a minor presence in this much larger community, appearing in about 1% of its papers, yet it accounts for about 31% of protactinium’s own recent research. This share is rising, having grown from about 25% in the previous period. A key anchor is the 2025 paper "Unlocking Novel δ and φ Bonding Modes in Actinides via Oxidation State Control," cited about 12 times, which explores these bonding modes.

A significant portion of the literature also belongs to Stable Isotope Geochemistry of Marine Sediments and Paleoenvironments. Here, protactinium serves as a geochemical tracer in studies of ocean circulation and climate models. While protactinium is a minor presence in this community—under 1% of its papers involve the element—it represents about 22% of protactinium’s recent research, a share that is rising from about 16% previously. The most cited work in this area is the 2022 IUPAC Technical Report "Standard atomic weights of the elements 2021," cited over 230 times, which establishes the foundational data for such isotopic studies.

Advanced Nuclear Reactor Materials and Corrosion Science constitutes another major area, where protactinium is studied as a burnable poison in water reactor and pressurized water reactor fuels. Protactinium is a minor presence in this community, appearing in under 1% of its papers, but it holds about 16% of protactinium’s recent research. This share is declining, down from about 23% in the earlier period. Notable work includes the 2022 study on VVER-1200 fuel assemblies using protactinium oxide, cited about 9 times.

Finally, Uranium Extraction, Separation, and Nuclear Fuel Cycle Chemistry accounts for about 6% of recent protactinium research, a share that is declining from about 13%. Protactinium is a minor presence here, involved in under 1% of the community's papers. The 2019 ICRP Publication 141, cited about 97 times, is a key reference in this domain, alongside recent work on separating protactinium from uranium-niobium alloys for radiochronometry.

Overall, the composition of protactinium research is shifting: the mono-oxo cation and geochemistry communities are gaining share, while reactor materials and fuel cycle chemistry are losing ground. The remaining 25% of research is distributed across other smaller communities.

For a deeper look at the element's current standing, consult the Last 12 Months and Executive Brief reports.