Dual-polymer strategy engineers a high-performance catalyst for green urea synthesis
image: This illustration shows the structure of the PDA/PEI-Ni-mSiOx catalyst, featuring a petal-like hollow architecture and atomic Ni−O−Si interfacial sites (inset), which work synergistically to convert CO2 and nitrate into urea efficiently under ambient conditions.
Credit: Nano Research, Tsinghua University Press
The industrial production of urea, a vital nitrogen fertilizer, has long relied on the energy-intensive Haber-Meiser process, which consumes vast amounts of energy and contributes significantly to global CO2 emissions. Now, a team of researchers has developed a new electrocatalyst that offers a green and efficient alternative, synthesizing urea from CO₂ and nitrate (NO3−) pollutants at room temperature.
The research team from Minnan Normal University, in collaboration with Nankai University, Fuzhou University, and Xiamen University, engineered a catalyst known as PDA/PEI-Ni-mSiOx. This catalyst features a unique petal-like hollow structure and, most importantly, atomic-level “Ni−O−Si” active sites created through a synergistic modification with two polymers: polydopamine (PDA) and polyethyleneimine (PEI).
The team published their findings in Nano Research on January 4, 2026.
“This work addresses two critical challenges simultaneously: reducing atmospheric CO2 and cleaning up nitrate contamination in water, while producing a valuable product,” said Jian-Feng Li, a senior author of the study. “Our dual-polymer approach is key. It allows us to precisely tailor the electronic environment at the catalyst’s surface, creating a highly active and stable interface for the crucial C−N bond formation.”
The dual-polymer modification was found to be crucial for the catalyst’s performance. The PDA provides strong adhesion and structural stability, while the nitrogen-rich PEI works in synergy to optimize the surface chemistry. This combination dramatically increases the proportion of catalytically critical nitrogen species, which act as anchors for reaction intermediates, accelerating the C−N coupling step necessary to form urea while suppressing competing side reactions like hydrogen evolution.
Under optimized conditions, the catalyst demonstrated outstanding performance, achieving a urea production rate of 2513 micrograms per hour per milligram of catalyst, with a high Faradaic efficiency of 28.6% and a urea selectivity of 54.2%. This means over half of the converted nitrate was selectively transformed into urea instead of other by-products like ammonia.
Perhaps even more critical for practical application, the catalyst exhibited exceptional durability. It retained over 90% of its initial activity after 39 hours of continuous operation, with detailed characterization confirming no significant structural degradation or loss of the active Ni−O−Si sites.
“The long-term stability is a result of the robust interface we constructed. The polymers not only enhance activity but also protect the active sites during electrolysis,” explained Yun Ling, another senior author. “This paves the way for the rational design of next-generation catalysts for sustainable electrochemical manufacturing.”
The researchers believe this strategy of using synergistic polymer modifications to engineer metal-oxide interfaces can be extended to other catalytic processes, opening new avenues for green chemistry and energy-saving technologies.
Other contributors included Weize Chen, Hui Su, Xiaoping Chen, Xuan Zheng, Zehua Zou, Jing Tang, Maosheng Zhang, and Qingxiang Wang from the collaborating institutions.
This work was supported by the National Natural Science Foundation of China (21872034, 22021001, and 92472203), the Natural Science Foundation of Fujian Province (2025J01363, 2024J01807, 2025J01973), the Natural Science Foundation of Zhangzhou City (ZZ2024J16), and the Eagle Project of Fujian Province.
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.