C01B 3/04 by decomposition of inorganic compounds
Introduced: January 1980
Last revised: January 2026
Full Title
Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen > Production of hydrogen; Production of gaseous mixtures containing hydrogen > by decomposition of inorganic compounds
Classification Context
- Section:
- CHEMISTRY; METALLURGY
- Class:
- INORGANIC CHEMISTRY
- Subclass:
- NON-METALLIC ELEMENTS; COMPOUNDS THEREOF
Filing statistics
IPC C01B 3/04 belongs to the parent subclass C01B, which recorded 251,225 patent applications worldwide between 2013 and 2023. Annual filings grew from 17,923 in 2013 to 29,649 in 2023 (+65%). The most active applicants in class C01 are CHINESE ACADEMY OF SCIENCES (5,794 applications), SINOPEC (CHINA PETROCHEMICAL CORPORATION) (3,286 applications) and LG CHEM (2,689 applications).
Source: EPO PATSTAT, worldwide filings
2 direct subcodes
Child Classifications
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- C01B 3/042 Decomposition of water
- C01B 3/047 Decomposition of ammonia
Top Applicants
Top 10 applicants by patent filingsfor class C01, 2013–2023, worldwide · Source: EPO PATSTAT
- CHINESE ACADEMY OF SCIENCES 5,794
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 3,286
- LG CHEM KR 2,689
- BASF (BADISCHE ANILIN & SODA FABRIK) DE 1,669
- CENTRAL SOUTH UNIVERSITY 1,531
- KMUST (KUNMING UNIVERSITY OF SCIENCE AND TECHNOLOGY) 1,252
- SUMITOMO METAL MINING COMPANY JP 1,073
- ZHEJIANG UNIVERSITY 1,061
- PANASONIC INTELLECTUAL PROPERTY JP 1,058
- PANASONIC INTELLECTUAL PROPERTY 1,038