Program Objective and Description

DARPA DSO is pursuing foundational technology for nitric acid generation via direct nitrogen oxidation.

Nitric acid is a critical chemical used in the manufacture of a wide range of defense- and civilian-relevant materials, including nitrate fertilizers; explosives for defense, mining, and construction; and industrial chemical manufacturing. Current nitric acid production is highly centralized, energy- and resource-intensive, and heavily reliant on foreign-supplied precursors. These considerations present a challenge for building and maintaining resilient supply chains for domestic food supply, weapons manufacture, and chemical industry. Recent advances in electrocatalysis and reactor design may enable highly energy-efficient production of nitric acid directly from air and water. This approach would not only break the dependence on foreign sources for precursor materials, but also reduce supply chain fragility and allow for decentralized production.

The HNO3 program aims to demonstrate nitric acid production at high rate and high energy efficiency from air and water as readily available precursors. The program will entail designing and developing catalysts and incorporating them into a full system to derisk the science, perform initial integration, and identify early-stage scale-up activities of a self-sufficient nitric acid generator from air, water, and energy.

Lightning Talks

Attendees may be afforded the opportunity to give a Lightning Talk (a 5-minute oral presentation) during the webcast outlining their interests and capabilities. The purpose of these presentations is to facilitate teaming discussions among the attendees. Upon registering, attendees may indicate if they would like to give a Lightning Talk. Due to limited availability, DARPA will accept submissions on a first-come, first-served basis and does not guarantee that an attendee’s requests to brief will be fulfilled. Submitted briefing materials should use the template and are limited to a single, PDF-format slide, which should be appropriate for public release, as they will be shared with the session via webcast. The slide must be submitted to HNO3@darpa.mil by noon 12:00 PM ET on December 10, 2025. DARPA will contact submitters upon receipt of their slide with additional guidance for the webcast.

CMO Q&A

DARPA Contracts Management Office (CMO) will be hosting a virtual contracting Q&A on December 17, 2025 from 2:00 PM – 3:00 PM ET. This is an opportunity for CMO to provide additional information on proposal submission, and proposer contracting personnel to ask any questions on how to propose to the forthcoming solicitation for HNO3. Interested personnel must register using the Proposers Day’s registration website (see Registration Information) for CMO Contracting Q&A.

To view the full Special Notice click the button below.

Event Participation (In-Person and Webcast)

Registration

There is no registration fee for the Proposers Day meeting or webcast. The registration deadline is Monday, December 8, 2025 at 4:00 PM ET or when capacity is reached, whichever comes first. Advance registration is required for attending the Proposers Day in-person and for receiving access to the webcast. The advance registration requirement applies to every individual intending to view the webcast either alone or as part of a group.

In-Person Attendance: Due to limitations of the conference facility space, physical attendance is restricted to the first 100 registrants with a maximum of five (5) individuals from any one organization and no more than two (2) representatives per division/department of that organization. Registrants in excess of the maximum capacity limitation may be added to a waitlist. If slots become available due to cancellations, the slots may be filled on a first come, first served basis from the waitlist.

Webcast Attendance: Registrants in excess of the maximum capacity limitation (250 individuals), may be added to a waitlist. If slots become available due to cancellations, the slots may be filled on a first come, first served basis from the waitlist.

Eligibility

DARPA hosts Proposers Day to: (1) promote teaming arrangements between researchers; (2) provide potential proposers with information on whether and how they might respond to the government’s research and development solicitations; and (3) increase efficiency in proposal preparation and evaluation. Therefore, Proposers Days are only open to registered potential proposers, i.e., the events are closed to the general public and media. For this particular program, Proposers Day registration is open to potential proposers who are U.S. citizens, U.S. permanent residents, and foreign nationals.

All registrants who are not U.S. Citizens must complete and submit either a DARPA Form 60 (U.S. Permanent Resident and Foreign National Visit Request – e.g., industry or academia) or an Official Visit Request (foreign government personnel, only) through the Embassy based in Washington, DC, no later than Friday, December 5, 2025 at 4:00 PM ET. Please note, this deadline is BEFORE the registration deadline of December 8th. Form 60 submission instructions are in the registration confirmation email. Contact the appropriate Embassy staff for assistance in submitting the Official Visit Request.

Upon entry to the physical meeting, all attendees will be required to present valid, Government-issued photo identification.

Meeting Location (In-Person)