Powering EVs and capturing CO2 with metal-organic frameworks

People and organizations around the world filed 3.55 million patent applications in 2023, an increase of 2.7% from 2022.

The rise continues a long-term trend. Applications doubled from 1995 to 2010 to about 2 million, according to the World Intellectual Property Organization (WIPO), and have grown steadily since then, with the exception of a dip in 2019.

It’s clear that patenting continues to be a key means for organizations to protect their intellectual property. And that’s also the case for chemistry-related IP. In 2022, the last year for which WIPO has aggregated reporting, more than 700,000 patents were filed in chemistry fields, including chemical engineering, organic chemistry, pharmaceuticals, and biotechnology, the organization says. Among those subdisciplines, patent applications grew fastest in chemical engineering, at an average rate of 8.5% from 2012 to 2022.

Despite the importance of patenting to the chemistry enterprise, Jason Lye, founder of the IP strategies and technical consulting firm Lyco Works, says not all chemists appreciate how patents spur innovation. He describes patents as a contract with the government. 

“If an inventor teaches the world exactly how they have achieved their invention, and provided that the patent office agrees that the invention is indeed new and not obvious, then the government will provide the inventor with a limited, legally enforceable monopoly on their specific invention.”

Lye cautions that, unlike scientific journals, patents are subject to neither peer review nor curation by an editor. For this reason, critical analysis—and a spoonful of skepticism—is needed to navigate this enormous body of knowledge, he says. But those who successfully do have access to a rich source of information and learning on practically every topic.

For this first in a series of graphic-rich columns exploring patent activity in notable areas of chemistry we have chosen metal-organic frameworks because of the intense interest these molecules have generated in both industry and academia. The series is being prepared in collaboration with CAS, a division of the American Chemical Society that specializes in scientific knowledge management. (C&EN is published by ACS but is editorially independent.)

Metal-organic frameworks (MOFs), discovered in the 1990s by the University of California, Berkeley, chemist Omar M. Yaghi, are objects of fascination in both academia and industry. MOFs are a large family of porous crystalline solids composed of metal ions or clusters joined by organic linkers. By tailoring the molecular building blocks, which control internal pore sizes and other features, researchers have made MOFs that feature extremely high internal surface area, including some that can adsorb exceptional amounts of gases such as hydrogen.

Patents granted to Contemporary Amperex Technology Co. Ltd. (CATL), ExxonMobil, and General Motors provide insight into the applications that major companies foresee for MOFs.

At China’s CATL, the world’s largest producer of lithium-ion batteries for electric vehicles (EVs), recent patent activity was, not surprisingly, focused on the use of MOFs in batteries. The firm’s biggest area of patenting is in the use of MOFs as battery separator materials. Also prominent are patents on MOFs used in battery cathode and anode materials. And CATL has a handful of patents on MOFs used in solar cell modules.

For ExxonMobil, a key focus of recent MOF patenting was on separating carbon dioxide, other gases, and hydrocarbons from mixed streams. A patent on capturing CO₂ from fossil fuel combustion, for example, describes a method of capturing more than 90% of CO₂ emissions “such that the emissions are negligible, essentially removing the CO₂ from the combustion air.” The oil company also holds patents on methods for producing MOFs, on chemical synthesis using MOFs, and on MOF-based gas storage and transportation methods.

Like CATL, General Motors has multiple patents on MOFs used in batteries. In addition, the US automaker has patents on the use of the materials in natural gas storage and in evaporative control canisters that store fuel vapors from auto gas tanks rather than releasing them into the environment. Anyone who has paid for an expensive repair after receiving a “check engine” light due to a faulty evaporative control canister will be in favor of improvements to these devices.