The corpus is led by large integrated refiners and catalyst manufacturers with long filing histories in hydroprocessing catalysis, several of which appear multiple times because their internal research institutes are recorded as separate assignees. This inflates headcount at the top without indicating separate competitive centres. When assessing concentration, group institute-level filers together with their parent company rather than counting them independently.

Filing activity rose from 36 records in 2017 to a peak of 66 in 2022, then declined toward the most recent partial year. Because publication lags filing by roughly 18 months, the last one to two years understate true activity, but the overall shape is a clear peak followed by a pullback rather than continued growth. That pattern is more consistent with a maturing field where core process-parameter claims are already staked out than with an emerging one.

This Sinopec filing claims an alumina support defined by a specific surface area of 40 to 160 m2/g, a total pore volume of 0.3 to 1.2 cm3/g, and a three-band pore-diameter distribution across sub-30 nm, 30-60 nm and above-60 nm ranges, plus a hydrogenation catalyst built on that support for selective hydrogenation of pyrolysis gasoline. Anyone designing a support that falls inside all of those numeric bands and pairs it with a hydrogenation catalyst for a similar feedstock risks overlap. Working outside at least one of the claimed ranges, or targeting a different catalytic application, is the more defensible position.

Relative to the dense coverage of pore-volume and calcination-temperature claims, this corpus shows comparatively thin filing around boehmite crystallite-size control, multi-modal pore distribution tailoring, rare-earth-doped stabilisation of the alumina phase, and exhaust-specific washcoat formulations. These sit adjacent to the heavily claimed core rather than outside the field entirely, so a first claim there should be drafted narrowly and checked against the full corpus rather than just the most-cited records.

B01J covers chemical and physical processes including catalysis, and 2,143 of the 2,239 records in this corpus are classified there even though the search terms are materials-science terms like boehmite precursor and specific surface area. That reflects a drafting choice: most applicants frame their alumina-support inventions as catalyst systems rather than standalone materials claims. It means a claim written around the synthesis or characterisation of the alumina itself, decoupled from a named catalytic use, sits in comparatively less-crowded territory.